title: Serum 25-hydroxyvitamin D levels in vitamin D-insufficient hip fracture patients after supplementation with ergocalciferol and cholecalciferol. Sunlight exposure or vitamin D supplementation for vitamin D-deficient non-western immigrants: a randomized clinical trial Effects of Combined Calcium and Vitamin D Supplementation on Insulin Secretion, Insulin Sensitivity and β-Cell Function in Multi-Ethnic Vitamin D-Deficient Adults at Risk for Type 2 Diabetes: A Pilot Randomized, Placebo-Controlled Trial Calcium and vitamin D intakes in children: a randomized controlled trial Vitamin D supplementation reduces insulin resistance in South Asian women living in New Zealand who are insulin resistant and vitamin D deficient - a randomised, placebo-controlled trial. Supplementation with 1000 IU vitamin D/d leads to parathyroid hormone suppression, but not increased fractional calcium absorption, in 4-8-y-old children: a double-blind randomized controlled trial. Does vitamin D supplementation of healthy Danish Caucasian girls affect bone turnover and bone mineralization? Vitamin D During Pregnancy and Infancy and Infant Serum 25-Hydroxyvitamin D Concentration Effect of vitamin D supplementation, directly or via breast milk for term infants, on serum 25 hydroxyvitamin D and related biochemistry, and propensity to infection: a randomised placebo-controlled trial. Vitamin D2 dose required to rapidly increase 25OHD levels in osteoporotic women Vitamin D Supplementation and Hemoglobin Levels in Hypertensive Patients: A Randomized Controlled Trial Effect of vitamin D supplementation on vitamin D status and bone turnover markers in young adults Evaluation of Vitamin D Supplementation Doses during Pregnancy in a Population at High Risk for Deficiency A dose–response study of vitamin D3 supplementation in healthy Chinese: a 5-arm randomized, placebo-controlled trial Effect of calcium plus vitamin D supplementation during pregnancy in Brazilian adolescent mothers: a randomized, placebo-controlled trial. Effect of Cholecalciferol therapy on serum FGF23 in vitamin D deficient patients: a randomized clinical trial Effect of High-Dose vs Standard-Dose Wintertime Vitamin D Supplementation on Viral Upper Respiratory Tract Infections in Young Healthy Children Effect of Vitamin D Supplementation on Obesity‐Induced Insulin Resistance: A Double‐Blind, Randomized, Placebo‐Controlled Trial Vitamin D and Testosterone in Healthy Men: A Randomized Controlled Trial Impact of Three Doses of Vitamin D3 on Serum 25(OH)D Deficiency and Insufficiency in At-Risk Schoolchildren Effects of Vitamin D Supplementation on Semen Quality, Reproductive Hormones, and Live Birth Rate: A Randomized Clinical Trial Effect of Low-Dose Vitamin D Supplementation on Serum 25(OH)D in School Children and White-Collar Workers Effects of Genetic and Nongenetic Factors on Total and Bioavailable 25(OH)D Responses to Vitamin D Supplementation Randomised Controlled Trial Comparing Daily Versus Depot Vitamin D3 Therapy in 0–16-Year-Old Newly Settled Refugees in Western Australia Over a Period of 40 Weeks Vitamin D supplementation reduces insulin resistance in Japanese adults: a secondary analysis of a double-blind, randomized, placebo-controlled trial. Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial. Vitamin D intake to attain a desired serum 25-hydroxyvitamin D concentration. Efficacy of daily and monthly high-dose calciferol in vitamin D-deficient nulliparous and lactating women. Effect of vitamin D supplementation on anthropometric indices among overweight and obese women: A double blind randomized controlled clinical trial. Estimation of the dietary requirement for vitamin D in healthy adolescent white girls. The relationship between maternal self-efficacy, compliance and outcome in a trial of vitamin D supplementation in pregnancy Maternal vitamin D supplementation in pregnancy and offspring outcomes: a double-blind randomized placebo-controlled trial Optimum dose of vitamin D for disease prevention in older people: BEST-D trial of vitamin D in primary care Vitamin D3 supplementation using an oral spray solution resolves deficiency but has no effect on VO2 max in Gaelic footballers: results from a randomised, double-blind, placebo-controlled trial A Randomized Double-Blind Placebo-Controlled Trial of the Effect of Vitamin D3 Supplementation on Breast Density in Premenopausal Women Efficacy of oral cholecalciferol on rhododendrol‐induced vitiligo: A blinded randomized clinical trial Dose response to vitamin D supplementation in African Americans: results of a 4-arm, randomized, placebo-controlled trial. Effect of vitamin D on musculoskeletal pain and headache: A randomized, double-blind, placebo-controlled trial among adult ethnic minorities in Norway Vitamin D and nifedipine in the treatment of Chinese patients with grades I-II essential hypertension: a randomized placebo-controlled trial. Effects of different doses of oral cholecalciferol on serum 25(OH)D, PTH, calcium and bone markers during fall and winter in schoolchildren Vitamin D supplementation during pregnancy: double-blind, randomized clinical trial of safety and effectiveness. Increased telomerase activity and vitamin D supplementation in overweight African Americans A Randomized, Double-Blind, Parallel Study to Evaluate the Dose-Response of Three Different Vitamin D Treatment Schemes on the 25-Hydroxyvitamin D Serum Concentration in Patients with Vitamin D Deficiency Effect of oral cholecalciferol 2,000 versus 5,000 IU on serum vitamin D, PTH, bone and muscle strength in patients with vitamin D deficiency Double Blind Study on the Need for Vitamin D Supplementation in Prepubertal Children Estimation of the dietary requirement for vitamin D in white children aged 4-8 y: a randomized, controlled, dose-response trial. Long-term vitamin D3 supplementation is more effective than vitamin D2 in maintaining serum 25-hydroxyvitamin D status over the winter months. The Effect of High-Dose Vitamin D Supplementation on Calciotropic Hormones and Bone Mineral Density in Obese Subjects with Low Levels of Circulating 25-Hydroxyvitamin D: Results from a Randomized Controlled Study Resolving Vitamin D Deficiency in the Preconception Period among High-Risk Reproductive Women: A Randomized Controlled Trial Randomized controlled trial of vitamin D supplementation in children with autism spectrum disorder Vitamin D supplementation during Antarctic winter. Effects of vitamin D supplementation and exercise training on physical performance in Chilean vitamin D deficient elderly subjects The effect of vitamin D supplementation on knee osteoarthritis, the VIDEO study: a randomised controlled trial. Effects of calcium and vitamin D supplementation on hip bone mineral density and calcium-related analytes in elderly ambulatory Australian women: a five-year randomized controlled trial. Effect of vitamin D supplementation on bone and vitamin D status among Pakistani immigrants in Denmark: a randomised double-blinded placebo-controlled intervention study. Determinants of the Maternal 25-Hydroxyvitamin D Response to Vitamin D Supplementation During Pregnancy Topical Delivery of Vitamin D3: A Randomized Controlled Pilot Study Vitamin D supplementation and growth in urban Mongol school children: Results from two randomized clinical trials Three doses of vitamin D, bone mineral density, and geometry in older women during modest weight control in a 1-year randomized controlled trial High-dose oral vitamin D3 supplementation in the elderly A Double-Blind, Placebo Controlled, Randomized Trial to Assess the Impact of a Monthly Administration of 50,000 IU of Vitamin D3 for 6 Months on Serum Levels of 25-Hydroxyvitamin D in Healthy Young Adults Changes in the human transcriptome upon vitamin D supplementation Vitamin D3 Loading Is Superior to Conventional Supplementation After Weight Loss Surgery in Vitamin D-Deficient Morbidly Obese Patients: a Double-Blind Randomized Placebo-Controlled Trial Vitamin D3 increases in abdominal subcutaneous fat tissue after supplementation with vitamin D3. Regional variation and determinants of vitamin D status in sunshine-abundant Thailand Effects of vitamin D supplementation on pulmonary function in postmenopausal women following an aquatic exercise program. Vitamin D3 and vitamin K1 supplementation of Dutch postmenopausal women with normal and low bone mineral densities: effects on serum 25-hydroxyvitamin D and carboxylated osteocalcin Genomic Response to Vitamin D Supplementation in the Setting of a Randomized, Placebo-Controlled Trial Prevalence of osteoporosis in ambulatory postmenopausal women from a semiurban region in Southern India: relationship to calcium nutrition and vitamin D status. Vitamin D requirements during lactation: high-dose maternal supplementation as therapy to prevent hypovitaminosis D for both the mother and the nursing infant. Estimations of Dietary Vitamin D Requirements in Black and White Children Vitamin D Supplementation and High-Density Lipoprotein Cholesterol: A Study in Healthy School Children Vitamin D Deficiency and Its Determinants in Adults: A Sample from Community-Based Settings in the United Arab Emirates The effect of high-dose vitamin D supplementation on serum vitamin D levels and milk calcium concentration in lactating women and their infants. Effect of vitamin D supplementation on bone health parameters of healthy young Indian women Increased vitamin D intake differentiated according to skin color is needed to meet requirements in young Swedish children during winter: a double-blind randomized clinical trial. Effect of Vitamin D and Calcium Supplementation on Cancer Incidence in Older Women: A Randomized Clinical Trial Prevention of bone loss by vitamin D supplementation in elderly women: a randomized double-blind trial. The effect of monthly 50 000 IU or 100 000 IU vitamin D supplements on vitamin D status in premenopausal Middle Eastern women living in Auckland The effects of season-long vitamin D supplementation on collegiate swimmers and divers. The effects of whole-body vibration training and vitamin D supplementation on muscle strength, muscle mass, and bone density in institutionalized elderly women: a 6-month randomized, controlled trial. Effect of weekly high-dose vitamin D3 supplementation on serum cholecalciferol concentrations in pregnant women Effect of two different doses of oral cholecalciferol supplementation on serum 25-hydroxy-vitamin D levels in healthy Indian postmenopausal women: A randomized controlled trial Vitamin D Status and Impact of Vitamin D3 and/or Calcium Supplementation in a Randomized Pilot Study in the Southeastern United States Effect of vitamin D supplementation on wintertime and overall bone loss in healthy postmenopausal women. Maintenance vitamin D3 dosage requirements in Chinese women with post menopausal osteoporosis living in the tropics. A randomized, placebo-controlled trial of vitamin D supplementation to improve glycaemia in overweight and obese African Americans. Cholecalciferol supplementation throughout winter does not affect markers of bone turnover in healthy young and elderly adults. Effects of Vitamin D and Exercise on the Wellbeing of Older Community-Dwelling Women: A Randomized Controlled Trial Effects of a long-term vitamin D and calcium supplementation on falls and parameters of muscle function in community-dwelling older individuals Does vitamin D3 supplementation improve glucose homeostasis in overweight or obese women? A double-blind, randomized, placebo-controlled clinical trial. Skeletal muscle strength in young Asian Indian females after vitamin D and calcium supplementation: a double-blind randomized controlled clinical trial. Effect of Vitamin D3 Supplementation in Black and in White Children: A Randomized, Placebo-Controlled Trial. Vitamin D3 supplementation during weight loss: a double-blind randomized controlled trial. The effects of vitamin D3 supplementation on serum total 25[OH]D concentration and physical performance: a randomised dose–response study A 250 μg/week dose of vitamin D was as effective as a 50 μg/d dose in healthy adults, but a regimen of four weekly followed by monthly doses of 1250 μg raised the risk of hypercalciuria. Optimal vitamin D status: a critical analysis on the basis of evidence-based medicine. Effect of vitamin D replacement on indexes of insulin resistance in overweight elderly individuals: a randomized controlled trial. A randomized controlled trial of vitamin D3 supplementation for the prevention of symptomatic upper respiratory tract infections. Prevalence of vitamin D deficiency and its associated factors in three regions of Saudi Arabia Vitamin D supplementation has no effect on insulin sensitivity or secretion in vitamin D-deficient, overweight or obese adults: a randomized placebo-controlled trial. Estimation of the dietary requirement for vitamin D in free-living adults >=64 y of age. Effect of isolated vitamin D supplementation on the rate of falls and postural balance in postmenopausal women fallers: a randomized, double-blind, placebo-controlled trial Impact of vitamin D supplementation during a resistance training intervention on body composition, muscle function, and glucose tolerance in overweight and obese adults. Effect of moderate-dose vitamin D supplementation on insulin sensitivity in vitamin D-deficient non-Western immigrants in the Netherlands: a randomized placebo-controlled trial. Skeletal and hormonal responses to vitamin D supplementation during sunlight deprivation in Antarctic expeditioners Effect of monthly high‐dose vitamin D on bone density in community‐dwelling older adults substudy of a randomized controlled trial Treatment of Vitamin D Insufficiency in Postmenopausal Women: A Randomized Clinical Trial. Effects of Vitamin D Supplementation on C-peptide and 25-hydroxyvitamin D Concentrations at 3 and 6 Months Estimation of the dietary requirement for vitamin D in adolescents aged 14-18 y: a dose-response, double-blind, randomized placebo-controlled trial. The response of elderly veterans to daily vitamin D3 supplementation of 2,000 IU: a pilot efficacy study. Vitamin D3 supplementation does not modify cardiovascular risk profile of adults with inadequate vitamin D status Effect of combined maternal and infant vitamin D supplementation on vitamin D status of exclusively breastfed infants. Vitamin D2 is as effective as vitamin D3 in maintaining circulating concentrations of 25-hydroxyvitamin D. A global study of vitamin D status and parathyroid function in postmenopausal women with osteoporosis: baseline data from the multiple outcomes of raloxifene evaluation clinical trial. The effect of calcium and vitamin D supplementation on bone health of male Jockeys. Does high dose vitamin D supplementation enhance cognition?: A randomized trial in healthy adults How Much Vitamin D3 Do the Elderly Need? Hip bone loss is attenuated with 1000 IU but not 400 IU daily vitamin D3: a 1-year double-blind RCT in postmenopausal women. High dose vitamin D may improve lower urinary tract symptoms in postmenopausal women Is a daily supplementation with 40 microgram vitamin D3 sufficient? A randomised controlled trial Serum concentrations of 1,25-dihydroxyvitamin D2 and 1,25-dihydroxyvitamin D3 in response to vitamin D2 and vitamin D3 supplementation. Randomized clinical trial to comparing efficacy of daily, weekly and monthly administration of vitamin D3 Daily supplementation with 15 μg vitamin D2 compared with vitamin D3 to increase wintertime 25-hydroxyvitamin D status in healthy South Asian and white European women: a 12-wk randomized, placebo-controlled food-fortification trial. Effect of treatment of vitamin D deficiency and insufficiency during pregnancy on fetal growth indices and maternal weight gain: a randomized clinical trial. Estimation of the dietary requirement for vitamin D in healthy adults.
abstract: Vitamin D insufficiency is commonly associated with hip fracture . However , the equipotency of ergocalciferol and cholecalciferol supplementation in this patient group has not been studied in a r and omized trial using high-performance liquid chromatography ( HPLC ) measurement of serum 25-hydroxyvitamin D ( 25OHD ) . The objective of this study was to determine if ergocalciferol and cholecalciferol are equipotent therapies in vitamin D-insufficient hip fracture patients . Ninety five hip fracture in patients with vitamin D insufficiency ( 25OHD<50 nmol/L ) were r and omized , double-blind , to treatment with ergocalciferol 1000 IU/day ( n=48 ) or cholecalciferol 1000 IU/day ( n=47 ) for three months . All participants were also given a placebo matching the alternative treatment to maintain blinding of treatment allocation . The primary endpoint was total serum 25OHD measured by HPLC . Secondary endpoints included 25OHD measured by radioimmunoassay ( RIA ) , intact parathyroid hormone ( iPTH ) , and bioactive ( 1 - 84 ) whole PTH ( wPTH ) .  Seventy patients ( 74 % ) completed the study with paired sample s for analysis . Cholecalciferol supplementation result ed in a 31 % greater increase in total HPLC-measured 25OHD ( p=0.010 ) and 52 % greater rise in RIA-measured 25OHD ( p<0.001 ) than supplementation with an equivalent dose of ergocalciferol . Changes in iPTH and wPTH were not significantly different between calciferol treatments ( p>0.05 ) . In vitamin D-insufficient hip fracture patients , supplementation with cholecalciferol 1000 IU/day for three months was more effective in increasing serum 25OHD than an equivalent dose of ergocalciferol . However , the lack of difference in PTH lowering between calciferol treatments raises questions about the biological importance of this observation Summary Vitamin D deficiency is very common in non-western immigrants . In this r and omized clinical trial , vitamin D 800 IU/day or 100,000 IU/3 months were compared with advised sunlight exposure . Vitamin D supplementation was more effective than advised sunlight exposure in improving vitamin D status and lowering parathyroid hormone levels . Introduction Vitamin D deficiency ( 25-hydroxyvitamin D [ 25(OH)D ] < 25 nmol/l ) is common among non-western immigrants . It can be treated with vitamin D supplementation or sunlight exposure . Methods To determine whether the effect of vitamin D3 supplementation ( daily 800 IU or 100,000 IU/3 months ) or sunlight exposure advice is similar with regard to serum 25(OH)D and parathyroid hormone ( PTH ) concentrations . R and omized clinical trial in 11 general practice s in The Netherl and s. Non-western immigrants , aged 18–65 years ( n = 232 ) and serum 25(OH)D < 25 nmol/l were r and omly assigned to supplementation ( daily 800 IU or 100,000 IU/3 months ) or advice for sunlight exposure for 6 months ( March – September ) . Blood sample s were collected at baseline , during treatment ( 3 months , 6 months ) , and at follow-up ( 12 months ) . Statistical analysis was performed with multilevel regression modelling . Results The intention-to-treat analysis included 211 persons . Baseline serum 25(OH)D was 22.5 ± 11.1 nmol/l . After 6 months , mean serum 25(OH)D increased to 53 nmol/l with 800 IU/day , to 50.5 nmol/l with 100,000 IU/3 months , and to 29.1 nmol/l with advised sunlight exposure ( supplementation vs sunshine p < 0.001 ) . Serum PTH decreased significantly in all groups after 3 months , more in the supplementation groups than in the advised sunlight group ( p < 0.05 ) . There was no significant effect on physical performance and functional limitations . Conclusion Vitamin D supplementation is more effective than advised sunlight exposure for treating vitamin D deficiency in non-western immigrants Objectives To examine whether combined vitamin D and calcium supplementation improves insulin sensitivity , insulin secretion , β-cell function , inflammation and metabolic markers . Design 6-month r and omized , placebo-controlled trial . Participants Ninety-five adults with serum 25-hydroxyvitamin D [ 25(OH)D ] ≤55 nmol/L at risk of type 2 diabetes ( with prediabetes or an AUSDRISK score ≥15 ) were r and omized . Analyses included participants who completed the baseline and final visits ( treatment n = 35 ; placebo n = 45 ) . Intervention Daily calcium carbonate ( 1,200 mg ) and cholecalciferol [ 2,000–6,000 IU to target 25(OH)D > 75 nmol/L ] or matching placebos for 6 months .  Measurements Insulin sensitivity ( HOMA2%S , Matsuda index ) , insulin secretion ( insulinogenic index , area under the curve ( AUC ) for C-peptide ) and β-cell function ( Matsuda index x AUC for C-peptide ) derived from a 75 g 2-h OGTT ; anthropometry ; blood pressure ; lipid profile ; hs-CRP ; TNF-α ; IL-6 ; adiponectin ; total and undercarboxylated osteocalcin . Results Participants were middle-aged adults ( mean age 54 years ; 69 % Europid ) at risk of type 2 diabetes ( 48 % with prediabetes ) . Compliance was > 80 % for calcium and vitamin D. Mean serum 25(OH)D concentration increased from 48 to 95 nmol/L in the treatment group ( 91 % achieved > 75 nmol/L ) , but remained unchanged in controls . There were no significant changes in insulin sensitivity , insulin secretion and β-cell function , or in inflammatory and metabolic markers between or within the groups , before or after adjustment for potential confounders including waist circumference and season of recruitment . In a post hoc analysis restricted to participants with prediabetes , a significant beneficial effect of vitamin D and calcium supplementation on insulin sensitivity ( HOMA%S and Matsuda ) was observed . Conclusions Daily vitamin D and calcium supplementation for 6 months may not change OGTT-derived measures of insulin sensitivity , insulin secretion and β-cell function in multi-ethnic adults with low vitamin D status at risk of type 2 diabetes . However , in participants with prediabetes , supplementation with vitamin D and calcium may improve insulin sensitivity . Trial Registration Australian New Zeal and Clinical Trials Registry Background Calcium ( Ca2 + ) and vitamin D ( VitD ) play an important role in child health . We evaluated the daily intake of Ca2 + and VitD in healthy children . Moreover , we demonstrate the efficacy of Ca2 + and VitD supplementation . Methods Daily Ca2 + and VitD intake was evaluated in consecutive healthy children through a vali date d question naire . Subjects with < 70 % of dietary reference intakes ( DRIs ) of Ca2 + and VitD were invited to participate in a prospect i ve r and omized trial with 2 groups of nutritional intervention : Group 1 , dietary counseling aim ing to optimize daily Ca2 + and VitD intake plus administration of a commercially available Ca2 + and VitD supplementation product ; Group 2 , dietary counseling alone . At the enrollment ( T0 ) and after 4 months ( T1 ) serum 25(OH ) Vitamin D levels were assessed . Results We evaluated 150 healthy children ( male 50 % , mean age 10 years ) ; at baseline a  low VitD intake  was observed in all subjects ( median 0.79 μg/die , IQR 1.78 ; range 0.01 - 5.02 ) ; this condition was associated with Ca2 + intake < 70 % of the DRIs in 82 subjects ( 55 % ) . At baseline serum 25(OH)D levels were low ( < 30 ng/ml ) in all study subjects and after 4 months of nutritional intervention , a normalization of serum 25(OH)D levels ( ≥30 ng/ml ) was observed in all children in Group 1 and in only one subject in Group 2 [ Group 1 : T1 33.8 ng/ml ( IQR 2.5 ) vs Group 2 : T1 24.5 ng/ml ( IQR 5.2 ) , p < 0.001 ] . Conclusions Adequate Ca2 + and VitD intakes are difficult to obtain through dietary counseling alone in pediatric subjects . Oral supplementation with of Ca2 + and VitD is a reliable strategy to prevent this condition . Trial registration The study was registered in Clinical Trials Protocol Registration System ( ID number : NCT01638494 ) Low serum 25-hydroxyvitamin D ( 25(OH)D ) has been shown to correlate with increased risk of type 2 diabetes . Small , observational studies suggest an action for vitamin D in improving insulin sensitivity and /or insulin secretion . The objective of the present study was to investigate the effect of improved vitamin D status on insulin resistance ( IR ) , utilising r and omised , controlled , double-blind intervention administering 100 microg ( 4000 IU ) vitamin D(3 ) ( n 42 ) or placebo ( n 39 ) daily for 6 months to South Asian women , aged 23 - 68 years , living in Auckl and , New Zeal and . Subjects were insulin resistant - homeostasis model assessment 1 (HOMA1)>1.93 and had serum 25(OH)D concentration < 50 nmol/l . Exclusion criteria included diabetes medication and vitamin D supplementation > 25 microg ( 1000 IU)/d . The HOMA2 computer model was used to calculate outcomes . Median ( 25th , 75th percentiles ) serum 25(OH)D(3 ) increased significantly from 21 ( 11 , 40 ) to 75 ( 55 , 84 ) nmol/l with supplementation . Significant improvements were seen in insulin sensitivity and IR ( P = 0.003 and 0.02 , respectively ) , and fasting insulin decreased ( P = 0.02 ) with supplementation compared with placebo . There was no change in C-peptide with supplementation . IR was most improved when endpoint serum 25(OH)D reached > or = 80 nmol/l . Secondary outcome variables ( lipid profile and high sensitivity C-reactive protein ) were not affected by supplementation . In conclusion , improving vitamin D status in insulin resistant women result ed in improved IR and sensitivity , but no change in insulin secretion . Optimal vitamin D concentrations for reducing IR were shown to be 80 - 119 nmol/l , providing further evidence for an increase in the recommended adequate levels . Registered Trial No. ACTRN12607000642482 BACKGROUND The effects of vitamin D supplementation in healthy prepubertal children on physiologic outcomes have not been investigated . OBJECTIVE The objective was to evaluate the effects of supplementation with 1000 IU vitamin D(3)/d on calcium absorption . DESIGN In a double-blind , placebo-controlled trial , we r and omly assigned 64 children to 1000 IU vitamin D(3)/d ( n = 32 ) or placebo ( n = 32 ) for 8 wk . Stable isotopes were used to assess calcium absorption . The main outcome measure was calcium absorption before and after supplementation . RESULTS All of the data are shown as means ± SDs . At baseline , vitamin D intake was 221 ± 79 IU/d and calcium intake was 830 ± 197 mg/d . Baseline serum 25-hydroxyvitamin D [ 25(OH)D ] was not significantly correlated with fractional or total calcium absorption . After 8 wk , with baseline values used as a covariate , no differences were seen in fractional or total calcium absorption based on supplementation group ( P = 0.75 and 0.36 , respectively ) . Supplemented children had a significant increase in 25(OH)D concentrations ( from 27.7 ± 7.4 to 36.0 ± 10.3 ng/mL ; P < 0.0001 ) and a decrease in parathyroid hormone ( from 21.4 ± 10.4 to 12.9 ± 7.1 pg/mL ; P < 0.001 ) ; no significant changes in the placebo group were observed . No adverse side effects were noted in either group . CONCLUSIONS Vitamin D(3 ) supplementation at 1000 IU/d increases 25(OH)D and decreases parathyroid hormone in children with average vitamin D intakes below the dietary recommendations of the Institute of Medicine . However , no significant effects of this change on calcium absorption occurred . This trial was registered at clinical trials.gov as NCT 00868738 INTRODUCTION A high peak bone mass may be essential for reducing the risk of osteoporosis later in life and a sufficient vitamin D level during puberty may be necessary for optimal bone accretion and obtaining a high peak bone mass . Dietary intake and synthesis during winter of vitamin D might be limited but the effect of vitamin D supplementation in adolescence on bone mass is not well established . OBJECTIVE To investigate the effect of supplementation with 5 and 10 microg/day vitamin D(3 ) for 12 months in 11- to 12-year-old girls on  bone mass and bone turnover as well as the possible influence of VDR and ER genotype on the effect of the supplementation . METHODS The girls ( n=221 ) were r and omized to receive either 5 microg or 10 microg vitamin D(3 ) supplementation per day or placebo for 12 months . Whole body and lumbar spine bone mass measured by DXA and pubertal status were determined at baseline and after 12 months whereas physical activity and dietary intake of calcium and vitamin D were assessed at baseline . Serum ( S ) 25-hydroxyvitamin D ( 25OHD ) , S-osteocalcin , S-parathyroid hormone , S-calcium , S-inorganic phosphate , urinary ( U ) pyridinoline ( Pyr ) and deoxpyridinoline ( Dpyr ) were measured at baseline and after 6 and 12 months . RESULTS The S-25OHD concentration increased ( p<0.001 ) relative to the baseline values in the groups receiving either 5 microg/day ( mean+/-SD ; 11.0+/-10.3 nmol/l , baseline 41.9+/-17.6 nmol/l ) or 10 microg/day ( 13.3+/-11.8 nmol/l , baseline 44.4+/-16.6 nmol/l ) vitamin D(3 ) for 12 months compared to placebo ( -3.1+/-9.8 nmol/l , baseline 43.4+/-17.1 nmol/l ) . There was no effect of vitamin D-supplementation on biomarkers for bone turnover or on whole body or spine bone mineral augmentation . However , vitamin D supplementation increased whole body bone mineral density ( BMD ) ( p=0.007 ) and bone mineral content ( BMC ) ( p=0.048 ) in the FF VDR genotype but not in the Ff or ff VDR genotypes . CONCLUSION Supplementation with vitamin D ( 5 or 10 microg/day ) over 12 months increased the S-25OHD concentration but there was no effect on indices of bone health in the entire group of girls . However , there was an effect on BMD for a subgroup with the FF VDR genotype indicating an influence of genotype OBJECTIVE : To determine the vitamin D dose necessary to achieve serum 25-hydroxyvitamin D ( 25(OH)D ) concentration ≥20 ng/mL during infancy . METHODS : A r and omized , double-blind , placebo-controlled trial in New Zeal and . Pregnant mothers , from 27 weeks ’ gestation to birth , and then their infants , from birth to age 6 months , were r and omly assigned to 1 of 3 mother/infant groups : placebo/placebo , vitamin D3 1000/400 IU , or vitamin D3 2000/800 IU . Serum 25(OH)D and calcium concentrations were measured at enrollment , 36 weeks ’ gestation , in cord blood , and in infants at 2 , 4 , and 6 months of age . RESULTS : Two-hundred- and -sixty pregnant women were r and omized . At enrollment , the proportions with serum 25(OH)D ≥20 ng/mL for placebo , lower-dose , and higher-dose groups were 54 % , 64 % , and 55 % , respectively . The proportion with 25(OH)D ≥20 ng/mL was larger in both intervention groups at 36 weeks ’ gestation ( 50 % , 91 % , 89 % , P < .001 ) . In comparison with placebo , the proportion of infants with 25(OH)D ≥20 ng/mL was larger in both intervention groups to age 4 months : cord blood ( 22 % , 72 % , 71 % , P < .001 ) , 2 months ( 50 % , 82 % , 92 % , P < .001 ) , and 4 months ( 66 % , 87 % , 87 % , P = .004 ) , but only in the higher-dose group at age 6 months ( 74 % , 82 % , 89 % , P = .07 ; higher dose versus placebo P = .03 , lower dose versus placebo P = .21 ) . CONCLUSIONS : Daily vitamin D supplementation during pregnancy and then infancy with 1000/400 IU or 2000/800 IU increases the proportion of infants with 25(OH)D ≥20 ng/mL , with the higher dose sustaining this increase for longer We assessed the effect of vitamin D supplementation on related biochemistry , infection and dentition of the infant . In a double-blind , placebo-controlled trial conducted in Lucknow , India ( latitude 26 ° N ) , 230 mother -newborn pairs were r and omised to receive , for 9 months , 3000µg/month oral vitamin D3 by the mother ( group A ) or 10µg/d by the infant ( group B ) or double placebo ( group C ) . All babies received 15 min of sun exposure ( unclothed ) during massage . Infants ' median 25-hydroxyvitamin D ( 25(OH)D ) was lower in group C ( median 45·3 ; interquartile range ( IQR ) 22 - 59·5 nmol/l ) than in groups A ( median 60·8 ; IQR 41·3 - 80·5 nmol/l ( P7.5µkat/l ) was significantly more frequent in group C babies ( 16 % ) than in group A ( 4 % ) or group B ( 0 % ) babies . The number of days with respiratory or diarrhoeal infection by 9 months of age was higher in group C ( median 46·5 ; IQR 14·8 - 73·3 d ) than in group A ( median 18·5 ; IQR 8·8 - 31·0 d ( P<0·01 ) ) or group B ( median 13·0 ; IQR 7·0 - 28·5 ( P<0·05 ) ) . We conclude that monthly maternal or daily infant supplementation with vitamin D along with sun exposure is superior to sun exposure alone in maintaining normal infant 25(OH)D at 3·5 months , and provide protection from elevated alkaline phosphatase and infectious morbidity Objective : Assessment of the effectiveness and safety of high daily 125 μg ( 5000 IU ) or 250 μg ( 10 000IU ) doses of vitamin D2 during 3 months , in rapidly obtaining adequate 25 hydroxyvitamin D ( 25OHD ) levels . Design : Longitudinal study .Subjects : Postmenopausal osteopenic/osteoporotic women ( n=38 ) were studied during winter and spring . Median age ( 25–75th percentile ) was 61.5 ( 57.00–66.25 ) years , and mean bone mineral density ( BMD ) was 0.902 (0.800–1.042)g/cm2 . Subjects were r and omly divided into three groups : control group ( n=13 ) : no vitamin D2 , 125 μg/day ( n=13 ) and 250 μg/day ( n=12 ) of vitamin D2 groups , all receiving 500 mg calcium/day . Serum calcium , phosphate , bone alkaline phosphatase ( BAP ) , C-telopeptide ( CTX ) , 25OHD , mid-molecule parathyroid hormone ( mmPTH ) , daily urinary calcium and creatinine excretion were determined at baseline and monthly . Results : For all subjects ( n=38 ) , the median baseline 25 hydroxyvitamin D ( 25OHD ) level was 36.25 ( 27.5–48.12 ) nmol/l . After 3 months , 8 % of the patients in the control group , 50 % in the 125 μg/day group and 75 % in the 250 μg/day group had 25OHD values above 85 nmol/l ( 34 ng/ml ) . Considering both vitamin D2 groups together , mmPTH and BAP levels diminished significantly after 3 months ( P<0.02 ) , unlike those of CTX . Serum calcium remained within normal range during the follow-up . Conclusions : The oral dose of vitamin D2 required to rapidly achieve adequate levels of 25OHD is seemingly much higher than the usual recommended vitamin D3 dose ( 20 μg/day ) . During 3 months , 250 μg/day of vitamin D2 most effectively raised 25OHD levels to 85 nmol/l in 75 % of the postmenopausal osteopenic/osteoporotic women treated Epidemiological evidence suggests that circulating 25-hydroxyvitamin D ( 25OHD ) levels are inversely associated with hemoglobin ( Hb ) levels and anemia risk . We evaluated whether vitamin D supplementation improves Hb levels and reduces anemia risk in hypertensive patients . Two hundred patients with 25OHD levels < 75 nmol/L who attended the Styrian Vitamin D Hypertension Trial were included , of whom 188 completed the trial . Patients r and omly received 2800 IU vitamin D3 daily or a matching placebo for eight weeks . Initially , the prevalence of anemic status ( Hb levels < 12.5 g/dL ) and deficient 25OHD levels ( < 30 nmol/L ) was 6.5 % and 7.5 % , respectively . All anemic patients had 25OHD levels > 50 nmol/L. The mean ( 95 % confidence interval ) vitamin D effect on Hb levels was 0.04 ( −0.14 to 0.22 ) g/dL ( P = 0.661 ) . Moreover , vitamin D treatment did not influence anemic status significantly ( P > 0.999 ) . Likewise , vitamin D had no significant effect on Hb levels in the subgroups of anemic patients or in patients with initial 25OHD levels < 30 nmol/L. In conclusion , a daily vitamin D supplement of 2800 IU for eight weeks did not improve Hb levels or anemic status  in hypertensive patients . Future trials should focus on anemic patients with deficient 25OHD levels ( e.g. , < 30 nmol/L ) . This trial is registered with clinical trials.gov [ NCT02136771 ] Objective : To assess the vitamin D status of healthy young people living in Northern Irel and and the effect of vitamin D supplementation on vitamin D status and bone turnover . Design : Double-blinded r and omised controlled intervention study . Setting : University of Ulster , Coleraine , Northern Irel and .Subjects : In total , 30 apparently healthy students ( 15 male and 15 female subjects ) , aged 18–27 years , were recruited from the university , with 27 completing the intervention . Interventions : Subjects were r and omly assigned , to receive either 15 μg ( 600 IU ) vitamin D3 and 1500 mg calcium/day ( vitamin D group ) , or 1500 mg calcium/day ( control group ) for 8 weeks between January and March . Vitamin D status , bone turnover markers , serum calcium and parathyroid hormone concentrations were measured at baseline and post intervention . Results : At baseline , vitamin D status was low in both the vitamin D group ( 47.9 ( s.d . 16.0 ) ) and the control group ( 55.5 ( s.d . 18.6 ) nmol/l 25(OH)D ) . Post intervention vitamin D status was significantly higher in the vitamin D-treated group ( 86.5 ( s.d . 24.5 ) ) compared to the control group ( 48.3 ( s.d . 16.8 ) nmol/l ) ( P<0.0001 ) . There was no significant effect of supplementation on bone turnover markers or PTH concentrations . Conclusions : This study suggests that young adults in Northern Irel and do not consume an adequate daily dietary intake of vitamin D to maintain plasma vitamin D concentrations in the wintertime . A daily supplement of 15 μg vitamin D3 significantly increased vitamin D status in these individuals to levels of sufficiency . Achievement of an optimum vitamin D status among young adults may have future positive health implication Aim / Background : Vitamin D supplementation during pregnancy is a well-accepted recommendation worldwide ; however , the debate about the correct dose is ongoing . We aim ed to compare daily doses of 600 , 1,200 , and 2,000 IU in this r and omized , controlled study . Methods : The study group consisted of 91 pregnant women aged 16 - 42 years admitted to Kocaeli Maternity and Children Hospital between April 2011 and April 2012 . The participants were r and omly divided into 3 groups . 600 , 1,200 , and 2,000 IU/day of vitamin D was supplemented to group 1 ( control group , n = 31 ) , group 2 ( n = 31 ) , and group 3 ( n = 32 ) , respectively . Serum calcium , 25-hydroxyvitamin D ( 25OHD ) , and the calcium/creatinine ratio in spot urine sample s were measured in the follow-up period . The serum calcium and 25OHD levels of the mothers ' infants were measured as well . Results : The frequency of vitamin D sufficiency after supplementation was 80 % in group 3 and it was significantly higher than in groups 1 ( 42 % ) and 2 ( 39 % ) ( p = 0.03 ) . The frequency of vitamin D sufficiency in the infants of the participants was 91 % in group 3 and it was significantly higher than in groups 1 ( 36 % ) and 2 ( 52 % ) ( p = 0.006 ) . Conclusions : At least 2,000 IU/day of vitamin D is needed to ensure adequate vitamin D status in pregnancy and early infancy Abstract Purpose To determine the dose – response of vitamin D3 supplementation on serum 25-hydroxyvitamin D [ 25(OH)D ] among Chinese adults . Methods In this 5-arm , r and omized , double-blinded controlled trial , 76 healthy participants were assigned to orally administrate 0 , 400 , 800 , 1200 or 2000 IU/d of vitamin D3 for 16 weeks . Serum 25(OH)D , parathyroid hormone , calcium , biomarkers of liver and renal function were measured at multiple time points . Results The mean ( SD ) serum 25(OH)D at baseline was 31.6 ( 8.7 ) nmol/L , and the dose – response relationship was curvilinear with a plateau around 6 weeks for all doses . At week 16 , 25(OH)D was increased by 6.0 ( 6.5 ) , 21.7 ( 15.8 ) , 26.3 ( 12.6 ) , 32.0 ( 12.8 ) and 36.3 ( 26.0 ) nmol/L for 0 , 400 , 800 , 1200 and 2000 IU/d ( all P ≤ 0.002 ) , corresponding to approximately 19 , 53 , 67 , 77 and 80 % of reversion of vitamin D deficiency , respectively . Daily intake of 800 IU vitamin D3 reached a targeted 25(OH)D ≥ 30 nmol/L in at least 97.5 % of Chinese , but not a targeted 25(OH)D ≥ 50 nmol/L even with 2000 IU/d . Change of 25(OH)D was inversely associated with change of PTH concentration ( r = −0.39 , P < 0.001 ) after controlling for age and sex . No between-group differences were observed in terms of the change in serum calcium , alanine transaminase , aspartate aminotransferase , gamma-glutamyltransferase and creatinine ( P ≥ 0.22 ) . Conclusions Supplementation with 400 , 800 , 1200 or 2000 IU/d vitamin D could improve the vitamin D deficiency with various degrees . Whether 2000 IU/d vitamin D3 would generate a better result without side effect requires more studies with larger sample s in future BACKGROUND Pregnancy and lactation in adolescents with habitually low calcium intake may adversely affect maternal bone mass . OBJECTIVE We investigated the effect of calcium plus vitamin D supplementation during pregnancy on bone mass during lactation in Brazilian adolescent mothers with low-calcium diets ( ∼600 mg/d ) . DESIGN Pregnant adolescents ( 14 - 19 y ) r and omly received daily calcium ( 600 mg ) plus vitamin D3 ( 200 IU ) ( n = 30 ) or a placebo ( n = 26 ) from 26 wk of pregnancy ( baseline ) until parturition . The bone mineral content ( BMC ) , bone area ( BA ) , and bone mineral density ( BMD ) at the total body , lumbar spine , and hip ( total and femoral neck ) were evaluated by using dual-energy X-ray absorptiometry at 5 and 20 wk postpartum . Serum hormones and 25-hydroxyvitamin D [ 25(OH)D ] were measured . Group comparisons were adjusted for significant covariates . RESULTS The mean serum 25(OH)D concentration was 59 nmol/L at baseline . In comparison with the placebo , 25(OH)D tended to be 14 - 15 nmol/L higher postpartum in the supplemented group ( P = 0.08 ) . Total body and hip BMC and BMD decreased over time ( P ≤ 0.005 ) in both groups with a group × time interaction at the femoral neck ( P < 0.04 ) . Supplemented mothers had higher lumbar spine BA ( 6.7 % ; P = 0.002 ) and lumbar spine BMC ( 7.9 % , P = 0.08 ) than did mothers who consumed the placebo at 5 wk postpartum . At 20 wk postpartum , differences between groups were more evident , with higher lumbar spine BMC ( 13.9 % ) , lumbar spine BA ( 6.2 % ) , and lumbar spine BMD ( 10.6 % ) in the supplemented group ( P ≤ 0.008 ) . CONCLUSIONS Calcium plus vitamin D supplementation during pregnancy of adolescents with low calcium intake  results in higher lumbar spine bone mass and a reduced rate of femoral neck bone loss during lactation . Additional studies are required to determine whether bone effects are temporary or long-lasting . This trial was registered at clinical trials.gov as NCT01732328 Introduction Fibroblast growth factor-23 plays an important role in regulating systemic phosphate homeostasis , and vitamin D metabolism . However , the effect of Cholecalciferol therapy on FGF23 serum level in patients with vitamin D deficiency has not been studied , yet . Material s and methods This is a double-blind , r and omized clinical trial on 119 vitamin D deficient patients in 2016 . Biochemical variables of treatment and placebo groups were analyzed after 12 weeks of 50,000 IU of Cholecalciferol vs. placebo therapy once a week , by SPSS18 . Results After Cholecalciferol therapy , delta of serum PTH in treatment group was less than the controls ( P < 0.001 ) . However , delta values of serum 25(OH)D3 , 1,25(OH)2D3 and FGF23 in vitamin D treated group were more than the placebo-treated ones ( P < 0.001 , P = 0.002 , and P = 0.04 , respectively ) . Moreover , FGF23 serum level in treatment group was associated with serum calcium ( P = 0.005 , r = −0.256 ) , and serum 1,25(OH)2D3 ( P < 0.001 , r = 0.529 ) . Conclusions We propose that in these patients 1,25(OH)2D3 has a positive association with serum FGF23 , and hypostasized that serum calcium might be a down regulator of serum FGF23 Importance Epidemiological studies support a link between low 25-hydroxyvitamin D levels and a higher risk of viral upper respiratory tract infections . However , whether winter supplementation of vitamin D reduces the risk among children is unknown . Objective To determine whether high-dose vs st and ard-dose vitamin D supplementation reduces the incidence of wintertime upper respiratory tract infections in young children . Design , Setting , and Participants A r and omized clinical trial was conducted during the winter months between September 13 , 2011 , and June 30 , 2015 , among children aged 1 through 5 years enrolled in TARGet Kids ! , a multisite primary care practice –based research network in Toronto , Ontario , Canada . Interventions Three hundred forty-nine participants were r and omized to receive 2000 IU/d of vitamin D oral supplementation ( high-dose group ) vs 354 participants who were r and omized to receive 400 IU/d ( st and ard-dose group ) for a minimum of 4 months between September and May. Main Outcome Measures The primary outcome was the number of laboratory-confirmed viral upper respiratory tract infections based on parent-collected nasal swabs over the winter months . Secondary outcomes included the number of influenza infections , noninfluenza infections , parent-reported upper respiratory tract illnesses , time to first upper respiratory tract infection , and serum 25-hydroxyvitamin D levels at study termination . Results Among 703 participants who were r and omized ( mean age , 2.7 years , 57.7 % boys ) , 699 ( 99.4 % ) completed the trial . The mean number of laboratory-confirmed upper respiratory tract infections per child was 1.05 ( 95 % CI , 0.91 - 1.19 ) for the high-dose group and 1.03 ( 95 % CI , 0.90 - 1.16 ) for the st and ard-dose group , for a between-group difference of 0.02 ( 95 % CI , −0.17 to 0.21 ) per child . There was no statistically significant difference in number of laboratory-confirmed infections between groups ( incidence rate ratio [ RR ] , 0.97 ; 95 % CI , 0.80 - 1.16 ) . There was also no significant difference in the median time to the first laboratory-confirmed infection : 3.95 months ( 95 % CI , 3.02 - 5.95 months ) for the high-dose group vs 3.29 months ( 95 % CI , 2.66 - 4.14 months ) for the st and ard-dose group , or number of parent-reported upper respiratory tract illnesses between groups ( 625 for high-dose vs 600 for st and ard-dose groups , incidence RR , 1.01 ; 95 % CI , 0.88 - 1.16 ) . At study termination , serum 25-hydroxyvitamin D levels were 48.7 ng/mL ( 95 % CI , 46.9 - 50.5 ng/mL ) in the high-dose group and 36.8 ng/mL ( 95 % CI , 35.4 - 38.2 ng/mL ) in the st and ard-dose group . Conclusions and Relevance Among healthy children aged 1 to 5 years , daily administration of 2000 IU compared with 400 IU of vitamin D supplementation did not reduce overall wintertime upper respiratory tract infections . These findings do not support the routine use of high-dose vitamin D supplementation in children for the prevention of viral upper respiratory tract infections . Trial Registration clinical trials.gov Identifier : Objective The aim was to investigate whether vitamin D supplementation , combined with a hypocaloric diet , could have an independent effect on insulin sensitivity in subjects with both overweight and hypovitaminosis D. Changes from baseline in anthropometric parameters , body composition , glucose tolerance , and insulin secretion were considered as secondary outcomes . Methods Eighteen volunteers who were nondiabetic and vitamin D deficient and had BMI > 25 kg/m2 were r and omized ( 1:1 ) in a double‐blind manner to a hypocaloric diet + either oral cholecalciferol at 25,000 IU/wk or placebo for 3 months . Hyperinsulinemic‐euglycemic clamp to measure insulin sensitivity  was performed at baseline and after intervention . Results Body weight in both groups decreased significantly ( −7.5 % in the vitamin D group and −10 % in the placebo group ; P < 0.05 for both ) , with no between‐group differences . Serum 25‐hydroxyvitamin D levels in the vitamin D group increased considerably ( from 36.7 ± 13.2 nmol/L to 74.8 ± 18.7 nmol/L ; P < 0.001 ) . Insulin sensitivity in the vitamin D group improved ( from 4.6 ± 2.0 to 6.9 ± 3.3 mg·kg−1·min−1 ; P < 0.001 ) , whereas no changes were observed in the placebo group ( from 4.9 ± 1.1 to 5.1 ± 0.3 mg·kg−1·min−1 ; P = 0.84 ) . Conclusions Cholecalciferol supplementation , combined with a weight loss program , significantly improves insulin sensitivity in healthy subjects with obesity and might represent a personalized approach for insulin‐resistant subjects with obesity Context : Available evidence shows an association of vitamin D with and rogen levels in men . However , results from preliminary r and omized controlled trials ( RCTs ) are conflicting . Objective : To evaluate whether vitamin D supplementation increases total testosterone ( TT ) levels in healthy men . Design : The Graz Vitamin D&TT‐ RCT is a single‐center , double‐blind , r and omized , placebo‐controlled trial conducted between December 2012 and January 2017 . Setting : Endocrine outpatient clinic at the Medical University of Graz , Austria . Participants : Ninety‐eight healthy men with TT levels ≥10.4 nmol/L and 25‐hydroxyvitamin D [ 25(OH)D ] levels < 75 nmol/L completed the study . Intervention : Subjects were r and omly assigned to receive 20,000 IU/wk of vitamin D3 ( n = 50 ) or placebo ( n = 50 ) for 12 weeks . Main Outcome Measures : Primary outcome was TT measured using mass spectrometry . Secondary outcomes were free testosterone , sex hormone‐binding globulin , estradiol , follicle‐stimulating hormone , and luteinizing hormone levels ; free and rogen index ; metabolic characteristics ; and body composition . Results : In healthy men [ mean values ± st and ard deviation : age , 39 years ( ±13 years ) ; 25(OH)D level , 53.3 nmol/L ( ±18.3 nmol/L ) ; TT , 19.1 nmol/L ( ±5.6 nmol/l ) ] , no significant treatment effect on TT was found ; however , there were significant effects on quantitative insulin sensitivity check index ( QUICKI ) and a trend toward decreased Matsuda index . In the treatment group , median ( interquartile range ) changes for TT , QUICKI , and Matsuda index were 0.5 nmol/L ( −0.63 to 0.63 nmol/L ; P = 0.497 ) , −0.02 ( −0.04 to 0.01 ; P = 0.034 ) , and −0.9 ( −3.2 to 0.8 ; P = 0.051 ) , respectively . Conclusion : Vitamin D treatment had no effect on TT levels in middle‐aged healthy men with normal baseline TT , but it significantly decreased QUICKI . Additional studies investigating vitamin D effects on TT and insulin sensitivity in healthy men are required Objective We investigated the daily dose of vitamin D needed to achieve serum 25-hydroxyvitamin D [ 25(OH)D ] sufficiency among schoolchildren at risk for deficiency . Study Design The Daily D Health Study was a r and omized double-blind vitamin D supplementation trial among racially/ethnically diverse schoolchildren ( n = 685 ) in the northeastern United States . Children were supplemented with vitamin D3 at 600 , 1000 , or 2000 IU/d for 6 months . Measurements included serum 25(OH)D at baseline ( October to December ) , 3 months ( January to March ) , 6 months ( April to June ) , and 12 months ( 6 months after supplementation ) . Results At baseline , mean ± st and ard deviation serum 25(OH)D level was 22.0 ± 6.8 ng/mL , with 5.5 % severely vitamin D deficient ( < 12 ng/mL ) , 34.1 % deficient ( 12 to 19 ng/mL ) , 49.0 % insufficient ( 20 to 29 ng/mL ) , and 11.4 % sufficient ( ≥30 ng/mL ) . The lowest levels of serum 25(OH)D were found among black ( 17.9 ± 6.7 ng/mL ) and Asian children ( 18.9 ± 4.8 ng/mL ) , with no baseline differences by weight status . Serum 25(OH)D increased over 6 months in all three dose groups . The 2000 IU/d group achieved a higher mean serum 25(OH)D level than the other two dose groups ( 33.1 vs 26.3 and 27.5 ng/mL ; P < 0.001 ) , with 59.9 % of this group attaining sufficiency at 3 months and only 5.3 % remaining severely deficient/deficient at 6 months . All dose groups demonstrated a fall in 25(OH)D at 12 months . Conclusions Children at risk for vitamin D deficiency benefited from daily sustained supplementation of 2000 IU/d compared with lower doses closer to the current recommended daily allowance for vitamin D intake . This benefit occurred over the winter months , when serum 25(OH)D level tend to fall Context Results of animal models and cross-sectional cohort studies have suggested a beneficial role for vitamin D in male reproduction . Objective Determine the effect of vitamin D and calcium supplementation on semen quality in infertile men with serum 25-hydroxyvitamin-D ( 25OHD ) levels ≤50 nmol/L. Design A single-center , triple-blinded , r and omized clinical trial . Participants A total of 1427 infertile men were screened to include 330 ; 1002 men did not meet inclusion criteria and 95 did not wish to participate . Intervention The active group received cholecalciferol 300,000 IU initially , then 1400 IU cholecalciferol and 500 mg of calcium daily for 150 days ; the other group received placebo .  Results Serum concentrations of 25OHD and 1,25-dihydroxyvitamin D3 were significantly higher in men in the treatment group compared with the placebo group . Vitamin D supplementation was not associated with changes in semen parameters , although spontaneous pregnancies tended to be higher in couples in which the man was in the treatment group [ 7.3 % vs 2.4 % , Δ5.0 % ( -0.6 % ; 10.5 % ) ] . Vitamin D treatment in a subgroup of oligozoospermic men increased the chance for a live birth compared with placebo [ 35.6 % vs 18.3 % , Δ17.3 % ( 1.6 % ; 32.9 % ) ] . Moreover , serum inhibin B levels were higher in men deficient in vitamin D who were r and omly assigned to receive high-dose vitamin D [ 193 pg/mL vs 143 pg/mL , Δ49 pg/mL ( 8 ; 91 pg/mL ) ] ; however , the increase in sperm concentration was not significantly higher than in the placebo group ( P = 0.07 ) . Conclusion High-dose vitamin D supplementation did not improve semen quality in vitamin D-insufficient infertile men . The positive impact of vitamin D supplementation on live birth rate and serum inhibin B in oligozoospermic and vitamin D-deficient men may be of clinical importance and warrant verification by others Objective : Our study aim ed to investigate the nutritional vitamin D status of school children aged 9–15 years and white-collar workers in Zhejiang province , and evaluate the efficacy of low-dose-oral vitamin D supplementation in both population s. Methods : We conducted a prospect i ve controlled trial during March 2014 to November 2015 , comparing the efficacy of vitamin D supplements ( 400 IU/day ) with non-intervention for 18 months in school children aged 9–15 years . Meanwhile , a before-after study was conducted among white-collar workers for 1 year . Serum 25(OH)D concentration was measured at baseline and after vitamin D supplementation , respectively . Results : At the baseline , 95 % of school children and 84 % of adult participants had vitamin D deficiency ( < 20 ng/mL ) . In school children , no difference was observed between the intervention and control groups with regard to anthropometric data . Serum 25(OH)D concentrations of the school children intervention group , school children control group and white-collar workers were 12.77 ± 3.01 ng/mL , 14.17 ± 3.59 ng/mL and 16.58 ± 3.66 ng/mL at baseline and increased to 17.34 ± 3.78 ng/mL , 18.04 ± 4.01 ng/mL and 17.75 ± 5.36 ng/mL after vitamin D supplementation , respectively . Although , after adjusting for potential confounders , the 400 IU oral vitamin D supplementation increased serum 25(OH)D concentration in school children ( β = 0.81 , p = 0.0426 ) as well as in white-collar workers ( p = 0.0839 ) , the prevalence of vitamin D deficiency was still very high among school children ( 79.23 % in intervention group and 72.38 % in control group ) and white-collar workers ( 76.00 % ) . Conclusions : High prevalence of vitamin D deficiency was common in these two study population s. Daily doses of 400 IU oral vitamin D supplementation was not able to adequately increase serum 25(OH)D concentrations . A suitable recommendation regarding the level of vitamin D supplementation is required for this Chinese population Context Little is known about how genetic and nongenetic factors modify responses of vitamin D supplementation in nonwhite population s. Objective To investigate factors modifying 25-hydroxyvitamin D [ 25(OH)D ] and bioavailable 25(OH)D [ 25(OH)DBio ] responses after vitamin D3 supplementation . Design , Setting , Participants , and Intervention In this 20-week , r and omized , double-blinded , placebo-controlled trial , 448 Chinese with vitamin D deficiency received 2000 IU/d vitamin D3 or placebo . Main Outcome Measures Serum 25(OH)D , vitamin D-binding protein ( VDBP ) , parathyroid hormone ( PTH ) and calcium were measured , and 25(OH)DBio was calculated based on VDBP levels . Six common polymorphisms in vitamin D metabolism genes were genotyped . Results Between-arm net changes were + 30.6 ± 1.7 nmol/L for 25(OH)D , + 2.7 ± 0.2 nmol/L for 25(OH)DBio , and -5.2 ± 1.2 pg/mL for PTH , corresponding to 70 % [ 95 % confidence interval ( CI ) , 62.8 % to 77.2 % ] net reversion rate for vitamin D deficiency at week 20 ( P < 0.001 ) . Only 25(OH)DBio change was positively associated with calcium change ( P < 0.001 ) . Genetic factors ( GC-rs4588/GC-rs7041 , VDR-rs2228570 , and CYP2R1-rs10741657 ; P ≤ 0.04 ) showed stronger influences on 25(OH)D or 25(OH)DBio responses than nongenetic factors , including baseline value , body mass index , and sex . An inverse association of PTH-25(OH)D was demonstrated only at 25(OH)D of < 50.8 ( 95 % CI , 43.6 to 59.0 ) nmol/L. Conclusions Supplemented 2000 IU/d vitamin D3  raised 25(OH)D and 25(OH)DBio but was unable to correct deficiency in 25 % of Chinese participants , which might be partially attributed to the effect of genetic modification . More studies are needed to eluci date appropriate vitamin D recommendations for Asians and the potential clinical implication s of 25(OH)DBio Vitamin D deficiency is highly prevalent in newly settled refugees in Western Australia ( WA ) . If adherence to daily vitamin D therapy is problematic , depot therapy is a therapeutic alternative . The aim of this study was to compare daily versus depot treatment and factors influencing the therapeutic outcome . Newly settled refugees ( n = 151 ) with 25(OH)D levels less than 78 nmol/L were r and omised to receive daily or depot vitamin D therapy with eight weekly interval follow up to 40 weeks . Biochemical and clinical parameters were collected at each visit . Generalized Linear Mixed Models ( GLMM ) examined the longitudinal changes over time controlling for confounders including age , gender , treatment arm , season , country of refuge/origin and sun exposure score . Participants were aged 5.5 months to 16.0 years ( 75 males , 83 females ) . Both treatment groups achieved vitamin D sufficiency . The daily treatment group had significantly higher 25(OH)D levels at each visit post baseline and a higher proportion of participants with levels above 50 nmol/L at all time points . Time , treatment group , calcium and sun exposure score were significant predictors of 25(OH)D serum levels .  Depot vitamin D therapy is an alternative to daily treatment in this at-risk group of children and adolescents in whom treatment adherence is problematic Higher circulating 25-hydroxyvitamin D ( 25[OH]D ) concentration has been linked to a lower prevalence of insulin resistance and type 2 diabetes mellitus . However , r and omized controlled trials have not clarified the effect of vitamin D supplementation on insulin resistance in healthy adults . The objective of this study was to assess the effect of vitamin D supplementation for 1 year on insulin resistance ; the study was a secondary analysis of a clinical trial . We hypothesized that increased 25(OH)D concentration after vitamin D supplementation for 1 year would significantly improve insulin resistance .  Ninety-six healthy adults participated in this study , of whom 81 completed the study . The participants r and omly received daily either 420 IU vitamin D3 or placebo in a double-blind manner for 1 year . The levels of fasting insulin , glucose , and other parameters were assessed at baseline and after 1 year of intervention . Homeostasis model assessment of insulin resistance index was calculated from insulin and glucose levels . Visceral fat area and physical activity were also investigated . Serum 25(OH)D and 1,25-dihydroxyvitamin D concentrations were significantly increased by approximately 29.5 nmol/L and 7.0 pg/mL , respectively , after 1-year vitamin D supplementation . After vitamin D supplementation , fasting glucose levels and values of homeostasis model assessment of insulin resistance index significantly decreased from 88.3 to 85.3 mg/dL ( P < .01 ) and 1.17 to 0.84 ( P < .01 ) , respectively , and the results were independent of physical activity and visceral fat accumulation . In conclusion , the present study showed that vitamin D supplementation for 1 year effectively improves fasting glucose level and insulin resistance in healthy Japanese adults BACKGROUND Numerous observational studies have found supplemental calcium and vitamin D to be associated with reduced risk of common cancers . However , interventional studies to test this effect are lacking . OBJECTIVE The purpose of this analysis was to determine the efficacy of calcium alone and calcium plus vitamin D in reducing incident cancer risk  of all types . DESIGN This was a 4-y , population -based , double-blind , r and omized placebo-controlled trial . The primary outcome was fracture incidence , and the principal secondary outcome was cancer incidence . The subjects were 1179 community-dwelling women r and omly selected from the population of healthy postmenopausal women aged > 55 y in a 9-county rural area of Nebraska centered at latitude 41.4 degrees N. Subjects were r and omly assigned to receive 1400 - 1500 mg supplemental calcium/d alone ( Ca-only ) , supplemental calcium plus 1100 IU vitamin D3/d ( Ca + D ) , or placebo . RESULTS When analyzed by intention to treat , cancer incidence was lower in the Ca + D women than in the placebo control subjects ( P < 0.03 ) . With the use of logistic regression , the unadjusted relative risks ( RR ) of incident cancer in the Ca + D and Ca-only groups were 0.402 ( P = 0.01 ) and 0.532 ( P = 0.06 ) , respectively . When analysis was confined to cancers diagnosed after the first 12 mo , RR for the Ca + D group fell to 0.232 ( CI : 0.09 , 0.60 ; P < 0.005 ) but did not change significantly for the Ca-only group . In multiple logistic regression models , both treatment and serum 25-hydroxyvitamin D concentrations were significant , independent predictors of cancer risk . CONCLUSIONS Improving calcium and vitamin D nutritional status substantially reduces  all-cancer risk in postmenopausal women . This trial was registered at clinical trials.gov as NCT00352170 BACKGROUND Indirect evidence suggests that optimal vitamin D status is achieved with a serum 25-hydroxyvitamin D [ 25(OH)D ] concentration > 75 nmol/L. OBJECTIVE We aim ed to determine the intake of vitamin D(3 ) needed to raise serum 25(OH)D to > 75 nmol/L. DESIGN The design was a 6-mo , prospect i ve , r and omized , double-blinded , double-dummy , placebo-controlled study of vitamin D(3 ) supplementation .  Serum 25(OH)D was measured by  radioimmunoassay . Vitamin D(3 ) intake was adjusted every 2 mo by use of an algorithm based on serum 25(OH)D concentration . RESULTS A total of 138 subjects entered the study . After 2 dose adjustments , almost all active subjects attained concentrations of 25(OH)D > 75 nmol/L , and no subjects exceeded 220 nmol/L. The mean ( + /-SD ) slope at 9 wk [ defined as 25(OH)D change/baseline dose ] was 0.66 + /- 0.35 (nmol/L)/(microg/d ) and did not differ statistically between blacks and whites . The mean daily dose was 86 microg ( 3440 IU ) . The use of computer simulations to obtain the most participants within the range of 75 - 220 nmol/L predicted an optimal daily dose of 115 microg/d ( 4600 IU ) . No hypercalcemia or hypercalciuria was observed . CONCLUSIONS Determination of the intake required to attain serum 25(OH)D concentrations > 75 nmol/L must consider the wide variability in the dose-response curve and basal 25(OH)D concentrations . Projection of the dose-response curves observed in this convenience sample onto the population of the third National Health and Nutrition Examination Survey suggests a dose of 95 microg/d ( 3800 IU ) for those above a 25(OH)D threshold of 55 nmol/L and a dose of 125 microg/d ( 5000 IU ) for those below that threshold BACKGROUND We previously found a high prevalence of vitamin D deficiency and low medication regimen compliance in Arab and East Indian women residing in the United Arab Emirates ( UAE ) . The appropriate dosing regimen for improving vitamin D status in this population is not known . OBJECTIVE We aim ed to determine the efficacy of daily and monthly supplementation with vitamin D2 , the only high-dose calciferol available in the UAE , in lactating and nulliparous women . DESIGN Healthy lactating ( n = 90 ) and nulliparous ( n = 88 ) women were r and omly assigned to consume 2000 IU vitamin D2/d or 60,000 IU vitamin D2/mo for 3 mo . Serum 25-hydroxyvitamin D [ 25(OH)D ] concentrations were measured by radioimmunoassay at baseline and every month . RESULTS Most women had vitamin D deficiency [ ie , 25(OH)D < 50 nmol/L ] at study entry . Mean + /- SD 25(OH)D concentrations at 3 mo were significantly higher than baseline in both lactating ( 39.8 + /- 12.4 and 25.2 + /- 10.7 nmol/L , respectively ) and nulliparous ( 40.4 + /- 23.4 and 19.3 + /- 12.2 nmol/L , respectively ) women ( P < 0.001 for both ) . In total , vitamin D supplementation was effective in achieving serum 25(OH)D concentrations of > or=50 nmol/L in 21 ( 30 % ) of 71 women at endpoint . CONCLUSIONS Oral vitamin D2 supplementation with 2000 IU/d or 60,000 IU/mo for 3 mo was safe , and it increased serum 25(OH)D concentrations significantly ; however , only a small proportion of the women studied achieved concentrations of > or=50 nmol/L. This suggests that , when sunlight exposure is limited , doses of vitamin D2 higher than those currently studied may be needed . Monthly dosing appears to be a safe and effective alternative to daily dosing AIMS The aim of this study was to investigate effect of vitamin D supplementation on anthropometric indices among women with overweight and obesity . METHODS This double blind r and omize clinical trial was conducted on 66 overweight and obese women . Those in intervention group received oral supplement of vitamin D 50,000 IU ( 1250 mcg ) per 25 day and in control group participants received placebo for 3 months . Anthropometric indices were measured before and after 3 months intervention . Before the intervention a 24-h dietary recall ( 3 days ) were used to assess dietary intake of individuals . Independent t test and multivariate repeated measure were used to data analysis . RESULTS The mean difference of anthropometric indices , serum calcium , 25 ( OH ) D3 and serum PTH between the intervention and control groups were significant ( P < 0/05 ) . However , no significant differences in serum phosphorus between the intervention and control groups were seen . CONCLUSION Supplementation with vitamin D 50 μg for each day for 3 months result ed in a significant reduction in anthropometric indices in women with obesity and overweight with normal primary 25(OH ) D3 serum levels BACKGROUND Knowledge gaps have contributed to considerable variation ( between 0 and 15 μg/d ) in international dietary recommendations for  vitamin D in adolescents . OBJECTIVE We aim ed to establish the distribution of dietary vitamin D required to maintain serum 25-hydroxyvitamin D [ 25(OH)D ] concentrations above several proposed cutoffs ( 25 , 37.5 , 40 , and 50 nmol/L ) during wintertime in adolescent white girls . DESIGN Data ( baseline and 6 mo ) from 2 r and omized ,  placebo-controlled  , double-blind , 12-mo intervention studies in Danish ( 55 ° N ) and Finnish ( 60 ° N ) girls ( n = 144 ; mean age : 11.3 y ; mean vitamin D intake : 3.7 μg/d ) at vitamin D(3 ) supplementation amounts of 0 , 5 , and 10 μg/d were used . Serum 25(OH)D was measured with an HPLC assay in a central ized laboratory . RESULTS Clear dose-related increments ( P < 0.0001 ) in serum 25(OH)D with increasing supplemental vitamin D(3 ) were observed . The slope of the relation between vitamin D intake and serum 25(OH)D at the end of winter was 2.43 nmol ⋅ L(-1 ) ⋅ μg intake(-1 ) , and no difference in the slopes between Finnish and Danish girls was observed . The vitamin D intakes that maintained serum 25(OH)D concentrations at > 25 , > 37.5 , and > 50 nmol/L in 97.5 % of the sample were 8.3 , 13.5 , and 18.6 μg/d , respectively , whereas an intake of 6.3 μg/d maintained a serum 25(OH)D concentration > 40 nmol/L in 50 % of the sample . CONCLUSION The vitamin D intakes required to ensure that adequate vitamin D status [ defined variably as serum 25(OH)D > 25 and > 50 nmol/L ] is maintained during winter in the vast majority ( > 97.5 % ) of adolescent girls ( mean age : 11.3 y ) at northern latitudes ( > 55 ° N ) are 8.3 and 18.6 μg/d , respectively . This trial was registered at clinical trials.gov as NCT00267540 Summary In a r and omised controlled trial of vitamin D during pregnancy , we demonstrated that women with lower self-efficacy were more likely to experience practical problems with taking the trial medication and that this was associated with lower compliance and achieved 25(OH)-vitamin D concentrations . Introduction The relationship between self-efficacy ( the belief that one can carry out a behaviour ) , compliance with study protocol and outcome was explored within a r and omised , double-blind , placebo-controlled trial of vitamin D supplementation in pregnancy . Methods In the Maternal Vitamin D Osteoporosis Study ( MAVIDOS ) trial , women with circulating plasma 25(OH)-vitamin D of 25–100 nmol/l in early pregnancy were r and omised to either 1000 IU cholecalciferol/day or matched placebo from 14 weeks until delivery . Circulating 25(OH)-vitamin D concentrations were assessed at 14 and 34 weeks ’ gestation . A sequential sub- sample completed Schwarzer ’s General Self-Efficacy Scale at 14 and 34 weeks and the Problematic Experiences of Therapy Scale at 34 weeks . Women were interviewed about their experiences of the trial and interview transcripts analysed thematically . Results In 203 women , those with higher self-efficacy were less likely to experience practical problems taking the study medication ( odds ratio ( OR ) 0.81 ( 95 % confidence interval ( CI ) 0.69–0.95 ) , p = 0.01 ) . Over half reported practical problems associated with poorer compliance with the protocol requiring women to take the medication daily . Compliance in women who experienced practical problems was 94 % compared with 98 % for those with no problems ( p < 0.001 ) . Poorer compliance was also associated with lower concentrations of 25(OH)-D in late pregnancy in the treatment group ( β = 0.54 nmol/l ( 95 % CI 0.18–0.89 ) , p = 0.003 ) . Thematic analysis suggested common difficulties were remembering to take the medication every day and swallowing the large capsules . Conclusions These findings suggest that differences in self-efficacy influence trial outcomes . Such information may help clinicians anticipate responses to routine vitamin D supplementation in pregnancy and identify those who may need more support to comply . Trial registration IS RCT N82927713 , registered 11/04/2008 We studied bone mineral content ( BMC ) , bone mineral density ( BMD ) , and body composition in offspring of women supplemented with vitamin D during pregnancy . Pregnant women were r and omized to receive oral cholecalciferol 60,000 units 4 weekly ( group 1 ) , 8 weekly ( group 2 ) , or placebo ( group 3 ) . All received 1 g calcium daily ( groups 1 and 2 without , and group 3 with 400 units vitamin D ) . Offspring at 12–16 months underwent dual-energy X-ray absorptiometry .  Maternal hypovitaminosis D  at recruitment was common ( serum 25OHD < 50 nmol/L in 88 % ) and severe ( 25OHD < 25 nmol/L in 46 % ) . Groups 1 and 2 ( n = 23 and 13 , median age 14 months ) had higher cord blood 25OHD ( 47.8 ± 13.8 and 31.0 ± 14.0 nmol/L ) versus group 3 ( n = 16 , median age 16 months , 17.8 ± 13.5 nmol/L , p < 0.001 ) . Babies in group 3 had higher whole-body BMC ( 250.8 ± 42.5 gm ) and BMD ( 0.335 ± 0.033 gm/cm2 ) compared to group 1 ( 213.1 ± 46.2 gm and 0.295 ± 0.041 gm/cm2 ) and group 2 ( 202.9 ± 29.9 gm and 0.287 ± 0.023 gm/cm2 ) ( p = 0.006 and 0.001 , respectively ) . In multivariate analysis , age , weight z score , and lean body mass remained significant contributors to BMC . Parameters of body composition were comparable among the groups . Vitamin D supplementation to pregnant women with severe deficiency in doses that improved cord blood 25OHD did not result in improved bone health or body composition in offspring at 12–16 months , compared to a dose too small to improve 25OHD levels Summary This trial compared the effects of daily treatment with vitamin D or placebo for 1 year on blood tests of vitamin D status . The results demonstrated that daily 4000 IU vitamin D3 is required to achieve blood levels associated with lowest disease risks , and this dose should be tested in future trials for fracture prevention . Introduction The aim of this trial was to assess the effects of daily supplementation with vitamin D3 4000 IU ( 100 μg ) , 2000 IU ( 50 μg ) or placebo for 1 year on biochemical markers of vitamin D status in preparation for a large trial for prevention of fractures and other outcomes . Methods This is a r and omized placebo-controlled trial in 305 community-dwelling people aged 65 years or older in Oxfordshire , UK . Outcomes included biochemical markers of vitamin D status ( plasma 25-hydroxy-vitamin D [ 25[OH]D ] , parathyroid hormone [ PTH ] , calcium and alkaline phosphatase ) , cardiovascular risk factors and tests of physical function . Results Mean ( SD ) plasma 25(OH)D levels were 50 ( 18 ) nmol/L at baseline and increased to 137 ( 39 ) , 102 ( 25 ) and 53 ( 16 ) nmol/L after 12 months in those allocated 4000 IU , 2000 IU or placebo , respectively ( with 88 % , 70 % and 1 % of these groups achieving the pre-specified level of > 90 nmol/L ) . Neither dose of vitamin D3 was associated with significant deviation outside the normal range of PTH or albumin-corrected calcium . The additional effect on 25(OH)D levels of 4000 versus 2000 IU was similar in all subgroups except for body mass index , for which the further increase was smaller in overweight and obese participants compared with normal-weight participants . Supplementation with vitamin D had no significant effects on cardiovascular risk factors or on measures of physical function . Conclusions After accounting for average 70 % compliance in long-term trials , doses of 4000 IU vitamin D3 daily may be required to achieve plasma 25(OH)D levels associated with lowest disease risk in observational studies Purpose Vitamin D inadequacy is a global health concern in athletes as well as the general population . Whilst the role of vitamin D in skeletal health is well defined , there remains uncertainty over whether vitamin D supplementation has an added benefit beyond bone health . Methods This r and omised placebo-controlled trial in healthy male and female Gaelic footballers ( n = 42 ) investigated the effect of vitamin D3 supplementation [ 3000 IU ( 75 µg ) daily for 12 weeks , via an oral spray solution ] on VO2 max which was the primary outcome measure . Secondary outcomes included skeletal muscle and lung function . Results Supplementation significantly increased total 25-hydroxyvitamin D concentrations compared to the placebo group ( mean ± SD change from baseline , 36.31 ± 32.34 vs. 6.11 ± 23.93 nmol/L , respectively ; P = 0.006 ) . At baseline , 50 and 22 % of footballers presented with vitamin D insufficiency ( 31–49 nmol/L ) and deficiency ( < 30 nmol/L ) , respectively . Total 25-hydroxyvitamin D concentration did not significantly correlate with any measure of physical performance . Analysis of covariance ( ANCOVA ) models demonstrated that vitamin D supplementation over 12 weeks had no significant effect on VO2 max ( P = 0.375 ) , vertical jump height ( P = 0.797 ) , left and right h and grip strength ( P = 0.146 and P = 0.266 , respectively ) , forced vital capacity ( P = 0.573 ) or forced expiratory volume at 1 s ( P = 0.665 ) , after adjusting for confounders . The high prevalence of vitamin D inadequacy observed in this cohort of collegiate Gaelic footballers supports the need for vitamin D supplementation during wintertime to avoid being at risk of poor bone health . Conclusions Twelve-week daily supplementation with 3000 IU ( 75 µg ) vitamin D3 successfully resolved deficiency but did not have any significant effect on VO2 max , skeletal muscle or lung function Background : This double-blind , placebo-controlled parallel group trial assessed whether oral supplementation with 1,000 , 2,000 , or 3,000 IU/day vitamin D3 over one year reduces percent mammographic breast density in premenopausal women . Methods : The trial was conducted between October 2012 and June 2015 , among premenopausal female volunteers from Quebec City ( Quebec , Canada ) . Women were r and omized with ratio 1:1:1:1 to one of four study arms ( 1,000 , 2,000 , or 3,000 IU/day vitamin D3 or placebo ) . The primary outcome was mean change in percent mammographic breast density . Participants and research team were blinded to study arm assignment . Results : Participants ( n = 405 ) were r and omized to receive 1,000 ( n = 101 ) , 2,000 ( n = 104 ) , or 3,000 IU/day ( n = 101 ) vitamin D3 , or a placebo ( n = 99 ) . The primary analysis included 391 participants ( 96 , 99 , 100 , and 96 , respectively ) . After the one-year intervention , mean ± SE change in percent breast density in the arms 1,000 IU/day ( –5.5 % ± 0.5 % ) and 2,000 IU/day ( –5.9 % ± 0.5 % ) vitamin D3 was similar to that in the placebo arm ( −5.7 % ± 0.5 % ) ( P values = 1.0 ) . In the 3,000 IU/day vitamin D3  arm , percent breast density also declined but slightly less ( –3.8 % ± 0.5 % ) compared with placebo arm ( P = 0.03 ) . Adherence to intervention was excellent ( 92.8 % ) , and reporting of health problems was comparable among study arms ( P ≥ 0.95 ) . All participants had normal serum calcium . Conclusions : In premenopausal women , one-year supplementation with 1,000 , 2,000 , or 3,000 IU/day vitamin D3 result ed in a reduction of percent breast density no greater than that seen with the placebo . Impact : At doses of 1,000–3,000 IU/day , vitamin D supplementation will not reduce breast cancer risk through changes in breast density . Cancer Epidemiol Biomarkers Prev ; 26(8 ) ; 1233–41 . © 2017 AACR Rhododendrol ( RD ) , 4-(4-hydroxyphenyl)-2-butanol , inhibits melanin synthesis and has been used for skin-whitening cosmetic products . RD has been very effective in lightening skin pigmentation , but some persons have developed so-called RD vitiligo , in which vitiligo starts on the face , neck and h and s where topical RD has been applied and even extended over skin areas where RD has not been applied . RD vitiligo lesions in some patients have lasted for years and have been resistant to conventional vitiligo treatments . We examined the effects of cholecalciferol on RD vitiligo in a blinded r and omized clinical trial . Forty-eight female RD vitiligo patients were recruited for the trial and were r and omized into two groups : the vitamin D (VD)-intervention group that received daily 5000 IU cholecalciferol for 5 months and the control group . Three blinded investigators scored vitiligo improvement by comparing photographic images of baseline and at 5-month observation . Serum 25(OH)D3 of RD vitiligo patients was not significantly different from age-matched healthy volunteers . Twenty-two in the VD-intervention group and 23 in the control group completed the 5-month observation . Serum 25(OH)D3 levels were significantly increased after the 5-month VD intervention , while the control group did not change . The improvement scores were significantly higher in the VD-intervention group than the control group . The improvement scores were positively correlated with the serum 25(OH)D3 levels after the 5-month intervention period but not before the treatment . This blinded r and omized clinical trial showed favor in administrating 5000 IU cholecalciferol daily to RD vitiligo patients BACKGROUND Association studies have suggested that lower circulating 25-hydroxyvitamin D [ 25(OH)D ] in African Americans may partially underlie higher rates of cardiovascular disease and cancer in this population . Nonetheless , the relation between vitamin D supplementation and 25(OH)D concentrations in African Americans remains undefined . OBJECTIVE Our primary objective was to determine the dose-response relation between vitamin D and plasma 25(OH)D. DESIGN A total of 328 African Americans in Boston , MA , were enrolled over 3 winters from 2007 to 2010 and r and omly assigned to receive a placebo or 1000 , 2000 , or 4000 IU vitamin D₃/d for 3 mo . Subjects completed sociodemographic and dietary question naires , and plasma sample s were drawn at baseline and 3 and 6 mo . RESULTS Median plasma 25(OH)D concentrations at baseline were 15.1 , 16.2 , 13.9 , and 15.7 ng/mL for subjects r and omly assigned to receive the placebo or 1000 , 2000 , or 4000 IU/d , respectively ( P = 0.63 ) . The median plasma 25(OH)D concentration at 3 mo differed significantly between supplementation arms at 13.7 , 29.7 , 34.8 , and 45.9 ng/mL , respectively ( P < 0.001 ) . An estimated 1640 IU vitamin D₃/d was needed to raise the plasma 25(OH)D concentration to ≥ 20 ng/mL in ≥ 97.5 % of participants , whereas a dose of 4000 IU/d was needed to achieve concentrations ≥ 33 ng/mL in ≥ 80 % of subjects . No significant hypercalcemia was seen in a subset of participants . CONCLUSIONS Within African Americans , an estimated 1640 IU vitamin D₃/d was required to achieve concentrations of plasma 25(OH)D recommended by the Institute of Medicine , whereas 4000 IU/d was needed to reach concentrations predicted to reduce cancer and cardiovascular disease risk in prospect i ve observational studies . These results may be helpful for informing future trials of disease prevention Summary Vitamin D supplementation for 16 weeks did not reduce  musculoskeletal pain or headache in this r and omized , double‐blind , placebo‐controlled study among ethnic minorities living in Norway . ABSTRACT Immigrants from South Asia , the Middle East , and Africa living in Northern Europe frequently have low vitamin D levels and more pain compared to the native Western population . The aim of this study was to examine whether daily vitamin D3 ( 25 & mgr;g/d or 10 & mgr;g/d ) supplementation for 16 weeks would improve musculoskeletal pain or headache compared to placebo . This r and omized , double‐blind , placebo‐controlled , parallel‐group trial recruited 251 participants aged 18 to 50 years , and 215 ( 86 % ) attended the follow‐up visit .  The pain measures were occurrence , anatomical localization , and degree of musculoskeletal pain , as measured by visual analogue scale ( VAS ) score during the past 2 weeks . Headache was measured with VAS and the Headache Impact Test ( HIT‐6 ) question naire . At baseline , females reported more pain sites ( 4.7 ) than males ( 3.4 ) , and only 7 % reported no pain in the past 2 weeks . During the past 4 weeks , 63 % reported headache with a high mean HIT‐6 score of 60 ( SD 7 ) . At follow‐up , vitamin D level , measured as serum 25(OH)D3 , increased from 27 nmol/L to 52 nmol/L and from 27 nmol/L to 43 nmol/L in the 25‐&mgr;g and 10‐&mgr;g supplementation groups , respectively , whereas serum 25(OH)D3 did not change in the  placebo group . Pain scores and headache scores were improved at follow‐up compared with baseline . The use of vitamin D supplements , however , showed no significant effect on the occurrence , anatomical localization , and degree of pain or headache compared to placebo OBJECTIVES Low vitamin D status has been shown to be associated with hypertension . We planned to research the effect of vitamin D and nifedipine in the treatment of patients with essential hypertension . METHODS Patients with grade s I-II essential hypertension were enrolled in this single-center , double-blind ,  placebo-controlled trial in Beijing . All patients received a conventional antihypertensive drug ( nifedipine , 30 mg/d ) . One hundred and twenty-six patients were r and omly assigned to receive vitamin D ( n=63 , 2000 IU/d ) or a placebo ( n=63 ) as an add-on to nifedipine , by the method of permutated block r and omization . Ambulatory blood pressure monitoring was performed at baseline ( month 0 ) , at month 3 and at month 6 . RESULTS In vitamin D supplementation group , there was a significant increase in mean 25-hydroxyvitamin D levels from baseline ( 19.4 ± 11.6 ng/ml ) to 6 months ( 34.1 ± 12.2 ng/ml ; p<0.001 ) . At 6 months , the primary end points , a difference in the fall of 24-h mean blood pressure , between the groups was -6.2 mmHg ( 95 % CI -11.2 ; -1.1 ) for systolic blood pressure ( p<0.001 ) and -4.2 mmHg ( 95 % CI -8.8 ; -0.3 ) for diastolic blood pressure ( p<0.001 ) under intention to treat analysis . In patients with vitamin D < 30 ng/ml at baseline ( n=113 ) , 24-h mean blood pressure decreased by 7.1/5.7 mmHg ( p<0.001 ) . Safety and tolerability were similar among the two groups . CONCLUSIONS Vitamin D supplementation can reduce blood pressure in patients with hypertension , it can be an adjuvant therapy for patients with grade s I-II essential hypertension . CLINICAL TRIAL REGISTRATION This study was registered in the Chinese Clinical Trial Registry , it is available in Website : http://www.chictr.org/cn/ ; REGISTRATION NUMBER ChiCTR-ONC-13003840 Background / Objectives : Controversies surround the actual requirements of vitamin D in adolescents . We aim ed to assess the efficacy and safety of different doses of vitamin D in high schoolchildren of Taleghan ( latitude 36.5 ° N ) near Tehran . Subjects/ Methods : In a r and omized double-blind , placebo-controlled trial , 210 subjects , aged 14–20 years , 105 boys and 105 girls were assigned to three groups ; group A ( n=70 ) received 50 000 U oral cholecalciferol monthly ( equal to 1600 U per day ) , group B ( n=70 ) , 50 000 U bimonthly ( equal to 800 U/day ) and group C ( n=70 ) , placebo . The study began in November 2007 and continued until April 2008 . Serum 25(OH)D , parathyroid hormone ( PTH ) , calcium ( Ca ) and bone markers were measured . Results : At baseline , girls had significantly lower concentrations  of 25(OH)D  than boys ( 19.25±16 vs 40.5±14 nmol/l ) . Mean 25(OH)D increased from 32±22 to 60±27.5 and 28.25±14.5 to 45.75±24 in groups A and B , respectively ( P<0.001 ) ; however , it did not change over time in group C ( 29±18 vs 29±17.5 ) . Increment of mean 25(OH)D was higher in group A than in group B ( P<0.01 ) . In all groups , girls had lower concentrations of 25(OH)D than boys  ( P<0.001 ) . Serum Ca increased and PTH decreased in groups A and B ( P<0.001 ) . In group A , osteocalcin ( OC ) and bone-specific alkaline phosphatase increased ( P<0.001 ) , but in group B only OC increased ( P<0.001 ) . Urine C telopeptide and Ca did not change in all three groups ; no case of hypercalcemia was observed . Conclusions : Although monthly administration of 50 000 U vitamin D3 increased serum 25(OH)D significantly , it was apparently not enough to correct vitamin D deficiency especially in girls The need , safety , and effectiveness of vitamin D supplementation during pregnancy remain controversial . In this r and omized , controlled trial , women with a singleton pregnancy at 12 to 16 weeks ' gestation received 400 , 2000 , or 4000 IU of vitamin D(3 ) per day until delivery . The primary outcome was maternal/neonatal circulating 25-hydroxyvitamin D [ 25(OH)D ] concentration at delivery , with secondary outcomes of a 25(OH)D concentration of 80 nmol/L or greater achieved and the 25(OH)D concentration required to achieve maximal 1,25-dihydroxyvitamin D(3 ) [ 1,25(OH)(2)D(3 ) ] production . Of the 494 women enrolled , 350 women continued until delivery : Mean 25(OH)D concentrations by group at delivery and 1 month before delivery were significantly different ( p < 0.0001 ) , and the percent who achieved sufficiency was significantly different by group , greatest in 4000-IU group ( p < 0.0001 ) . The relative risk ( RR ) for achieving a concentration of 80 nmol/L or greater within 1 month of delivery was significantly different between the 2000- and the 400-IU groups ( RR = 1.52 , 95 % CI 1.24 - 1.86 ) , the 4000- and the 400-IU groups ( RR = 1.60 , 95 % CI 1.32 - 1.95 ) but not between the 4000- and . 2000-IU groups ( RR = 1.06 , 95 % CI 0.93 - 1.19 ) . Circulating 25(OH)D had a direct influence on circulating 1,25(OH)(2)D(3 ) concentrations throughout pregnancy ( p < 0.0001 ) , with maximal production of 1,25(OH)(2)D(3 ) in all strata in the 4000-IU group . There were no differences between groups on any safety measure . Not a single adverse event was attributed to vitamin D supplementation or circulating 25(OH)D levels . It is concluded that vitamin D supplementation of 4000 IU/d for pregnant women is safe and most effective in achieving sufficiency in all women and their neonates regardless of race , whereas the current estimated average requirement is comparatively ineffective at achieving adequate circulating 25(OH)D concentrations , especially in African Americans Objective : We aim ed to investigate whether vitamin D supplementation modulates peripheral blood mononuclear cell ( P BMC ) telomerase activity in overweight African Americans . Design : A double blind , r and omized and placebo-controlled clinical trial ( # NCT01141192 ) was recently conducted . Subjects And Methods : African-American adults were r and omly assigned to either the placebo , or the vitamin D group ( 60 000 IU per month ( equivalent to ∼2000 IU per day ) oral vitamin D3 supplementation ) . Fresh P BMC s were collected from 37 subjects ( 18 in the placebo group and 19 in the vitamin D group ) , both at baseline and 16 weeks . P BMC telomerase activity was measured by the telomeric repeat amplification protocol . Results : Serum 25 hydroxyvitamin D levels increased from 40.7±15.7 at baseline to 48.1±17.5 nmol l–1 at posttest ( P=0.004 ) in the placebo group , and from 35.4±11.3 at baseline to 103.7±31.5 nmol l–1 at posttests ( P<0.0001 ) in the vitamin D group . In the vitamin D group , P BMC telomerase activity increased by 19.2 % from baseline ( 1.56±0.29 absorbance reading unit ( AU ) ) to posttest ( 1.86±0.42 AU , P<0.0001 ) . The significance persisted after controlling for age , sex and body mass index ( P=0.039 ) . P BMC telomerase activity in the placebo group did not change from baseline ( 1.43±0.26 AU ) to posttest ( 1.46±0.27 AU , P=0.157 ) . Conclusion : Vitamin D supplementation significantly increased P BMC telomerase activity in overweight African Americans . Our data suggest that vitamin D may improve telomere maintenance and prevent cell senescence and counteract obesity-induced acceleration of cellular aging Many people worldwide are vitamin D ( VTD ) deficient or insufficient , and there is still no consensus on the dose of VTD that should be administered to achieve a 25(OH)D concentration of 20 or 30 ng/mL. In this study , we aim ed to determine an adapted supplementation of VTD able to quickly and safely increase the vitamin D status of healthy adults with low 25(OH)D. One hundred and fifty ( 150 ) subjects were r and omized into three groups , each to receive , orally , a loading dose of 50,000 , 100,000 or 200,000 IU of VTD3 at Week 0 , followed by 25,000 , 50,000 or 100,000 IU at Week 4 and Week 8 . Whereas 25(OH)D baseline values were not different between groups ( p = 0.42 ) , a significant increase was observed at Week 12 ( p < 0.0001 ) with a mean change from baseline of 7.72 ± 5.08 , 13.3 ± 5.88 and 20.12 ± 7.79 ng/mL. A plateau was reached after eight weeks . No related adverse event was recorded . This study demonstrated a linear dose-response relationship with an increase in 25(OH)D levels proportional to the dose administered . In conclusion , a loading dose of 200,000 IU VTD3 followed by a monthly dose of 100,000 IU is the best dosing schedule to quickly and safely correct the VTD status Summary Treatment of vitamin D deficiency for 3 months with oral cholecalciferol 5,000 IU daily was more effective than 2,000 IU daily in achieving optimal serum 25-hydroxyvitamin D ( 25OHD ) concentrations . Optimal 25OHD serum level calculated to be 63.8 nmol/L. All parameters of muscle strength improved following administration of cholecalciferol for 3 months . Introduction The aim of this study was to determine the optimal dose of cholecalciferol required to achieve target serum 25OHD level ≥75 nmol/L and its relationship to both bone turnover and muscle strength . Methods Thirty deficient patients ( serum 25OHD ≤50 nmol/L ) were r and omly assigned into two groups — i.e . 2,000 and 5,000 IU/day . Data were collected at baseline , at 2 and 3 months post-therapy : ( a ) clinical demographics , ( b ) dietary calcium recall , ( c ) physical tests of muscle function and ( d ) biochemistry . Statistical analysis used paired student t test and analysis of variance . Regression analysis was used to determine relationship between serum 25OHD and parathyroid hormone ( PTH ) . Results Twenty-six ( 87 % ) patients completed 3 months of therapy . The percent increase in serum 25OHD ( compared to baseline ) was 82.7 % in 2,000-IU group and 219.5 % in 5,000-IU group . All participants ( 100 % ) achieved a serum 25OHD concentration > 50 nmol/L ; only 5 subjects ( 45.4 % ) in 2,000-IU group compared to 14 subjects ( 93.3 % ) in 5,000-IU group achieved final 25OHD concentration ≥75 nmol/L ( p < 0.01 ) . In the regression analysis , the reflexion point at which the PTH level increased above the normal range was calculated to be 63.8 nmol/L 25OHD . All parameters of muscle strength showed trends in improvements following the administration of both the 2,000 and 5,000 IU doses . No patient reported untoward side effects and no patient developed hypercalcaemia . Conclusion Treatment for 3 months with oral cholecalciferol 5,000 IU daily may be more effective than 2,000 IU daily in achieving optimal serum 25OHD concentrations in vitamin D-deficient patients ABSTRACT . Fifty‐one healthy prepubertal schoolchildren were followed for 13 months in a double blind study . Twenty‐four of them were supplemented with 400 IU of vitamin D2 5–7 times weekly , while 27 received a placebo . The children were examined in winter both at the beginning and at the end of the study , and in the middle of the study in autumn . Mean 25‐hydroxyvitamin D levels in the supplemented group were significantly higher than those in the placebo group both in autumn and in winter , when the study ended . The vitamin D supplementation did not , however , affect other vitamin D metabolites , serum calcium , albumin , inorganic phosphorus , parathyroid hormone concentrations or alkaline phosphatase activity . Moreover , the supplementation caused no alterations in the weight or height gain or bone mineral content of the distal radius of the children , and thus sub clinical rickets could not be shown BACKGROUND Children in northern latitudes are at high risk of vitamin D deficiency during winter because of negligible dermal vitamin D3 production . However , to our knowledge , the dietary requirement for maintaining the nutritional adequacy of vitamin D in young children has not been investigated . OBJECTIVE We aim ed to establish the distribution of vitamin D intakes required to maintain winter serum 25-hydroxyvitamin D [ 25(OH)D ] concentrations above the proposed cutoffs ( 25 , 30 , 40 , and 50 nmol/L ) in white Danish children aged 4 - 8 y living at 55 ° N. DESIGN In a double-blind , r and omized , controlled trial 119 children ( mean age : 6.7 y ) were assigned to 0 ( placebo ) , 10 , or 20 μg vitamin D3/d supplementation for 20 wk . We measured anthropometry , dietary vitamin D , and serum 25(OH)D with liquid chromatography-t and em mass spectrometry at baseline and endpoint . RESULTS The mean ± SD baseline serum 25(OH)D was 56.7 ± 12.3 nmol/L ( range : 28.7 - 101.4 nmol/L ) . Serum 25(OH)D increased by a mean ± SE of 4.9 ± 1.3 and 17.7 ± 1.8 nmol/L in the groups receiving 10 and 20 μg vitamin D3/d , respectively , and decreased by 24.1 ± 1.2 nmol/L in the placebo group ( P < 0.001 ) . A nonlinear model of serum 25(OH)D as a function of total vitamin D intake ( diet and supplements ) was fit to the data . The estimated vitamin D intakes required to maintain winter serum 25(OH)D > 30 ( avoiding deficiency ) and > 50 nmol/L ( ensuring adequacy ) in 97.5 % of participants were 8.3 and 19.5 μg/d , respectively , and 4.4 μg/d was required to maintain serum 25(OH)D > 40 nmol/L in 50 % of participants . CONCLUSIONS Vitamin D intakes between 8 and 20 μg/d are required by white 4- to 8-y-olds during winter in northern latitudes to maintain serum 25(OH)D > 30 - 50 nmol/L depending on chosen serum 25(OH)D threshold . This trial was registered at clinical trials.gov as NCT02145195 Public health recommendations do not distinguish between vitamin D2 and vitamin D3 , yet disagreement exists on whether these two forms should be considered equivalent . The objective of the present study was to evaluate the effect of a daily physiological dose of vitamin D2 or vitamin D3 on 25-hydroxyvitamin D ( 25(OH)D ) status over the winter months in healthy adults living in Dunedin , New Zeal and ( latitude 46 ° S ) . Participants aged 18 - 50 years were r and omly assigned to 25 μg ( 1000 IU ) vitamin D3 ( n 32 ) , 25 μg ( 1000 IU ) vitamin D2 ( n 31 ) or placebo ( n 32 ) daily for 25 weeks beginning at the end of summer . A per- protocol approach , which included ≥ 90 % supplement compliance , was used for all analyses . Serum 25-hydroxyvitamin D3 ( 25(OH)D3 ) , 25-hydroxyvitamin D2 ( 25(OH)D2 ) and parathyroid hormone ( PTH ) were measured at baseline and at 4 , 8 , 13 and 25 weeks . Geometric mean total serum 25(OH)D concentrations ( sum of 25(OH)D2 and 25(OH)D3 ) at baseline was 80 nmol/l . After 25 weeks , participants r and omised to D2 and placebo had a significant reduction in serum 25(OH)D3 concentrations over the winter months compared with vitamin D3-supplemented participants ( both P < 0.001 ) . Supplementation with vitamin D2  increased serum 25(OH)D2 but produced a 9 ( 95 % CI 1 , 17 ) nmol/l greater decline in the 25(OH)D3 metabolite compared with placebo ( P < 0.036 ) . Overall , total serum 25(OH)D concentrations were 21 ( 95 % CI 14 , 30 ) nmol/l lower in participants receiving vitamin D2 compared with those receiving D3 ( P < 0.001 ) , among whom total serum 25(OH)D concentrations remained unchanged . No intervention-related changes in PTH were observed . Daily supplementation of vitamin D3 was more effective than D2 ; however , the functional consequence of the differing metabolic response warrants further investigation Low levels of 25-hydroxyvitamin D ( 25OHD ) are associated with increased bone turnover and risk of fractures . Plasma 25OHD is inversely related to body mass index , and vitamin D deficiency is common in obesity . We aim ed to determine whether vitamin D supplementation affects bone turnover and bone mineral density ( BMD ) in obese subjects . Fifty-two healthy obese men and women aged 18–50 years with plasma 25OHD levels below 50 nmol/L were r and omized to 7,000 IU of cholecalciferol daily or placebo for 26 weeks . We measured plasma levels of 25OHD , parathyroid hormone ( PTH ) , and markers of bone turnover , as well as BMD at the hip , spine , forearm , and whole body . Compared with placebo , treatment with cholecalciferol  increased mean plasma 25OHD from 35 to 110 nmol/L ( p < 0.00001 ) and significantly decreased PTH ( p < 0.05 ) . BMD increased significantly at the forearm by 1.6 ± 0.7 % ( p = 0.03 ) . The bone resorption marker C-terminal telopetide of type 1 collagen ( CTX ) decreased borderline significantly in the cholecalciferol group compared with the placebo group ( p = 0.07 ) . Changes in plasma 25OHD correlated inversely with changes in plasma levels of bone-specific alkaline phosphatase ( r = −0.38 , p = 0.01 ) and CTX ( r = −0.33 , p = 0.03 ) . Changes in CTX correlated inversely with changes in spine BMD ( r = −0.45 , p = 0.04 ) . Increasing circulating 25OHD levels by cholecalciferol treatment is of importance to bone health in young obese subjects as increased levels of 25OHD are associated with a decrease in both PTH and bone turnover and with an increase in BMD at the forearm Background : Although vitamin D deficiency has been linked to potential complications in reproductive women , the recommended intake dosage of this vitamin in population s with high incidence of deficiency in preconception period has not been defined . Objectives : The study investigated the effect of consuming a dosage of 2000 IU/day oral vitamin D for 105 days , on serum levels of this vitamin in reproductive women . Material s and Methods : 229 women with 18 - 35 years old , who were confirmed to be vitamin D deficient ( vitamin D < 75 nmol/L ) , were r and omized into the intervention and control groups and after 15 weeks consumption of the supplement and placebo , their serum sample s were obtained . Results : At baseline the mean serum levels of vitamin D in the control group was 23.34 ± 15.87 nmol/L and in intervention group was 25.13 ± 18.46 nmol/L , that these values did n’t have any significant difference ( P = 0.43 ) , while after intervention , significant differences between the two groups was noticed ( P < 0.001 ) . The affecting factors to achieve normal range of vitamin D in the intervention group included basal amounts of vitamin D and two underlying factors based on question naire data : use of oral supplements ( except vitamin D and calcium ) in daily life and perfect sun exposure . Conclusion : This study showed positive effect of the 2000 IU/day oral vitamin D on the serum level elevation of this vitamin in reproductive women BACKGROUND Autism spectrum disorder ( ASD ) is a frequent developmental disorder characterized by pervasive deficits in social interaction , impairment in verbal and nonverbal communication , and stereotyped patterns of interests and activities . It has been previously reported that there is vitamin D deficiency in autistic children ; however , there is a lack of r and omized controlled trials of vitamin D supplementation in ASD children . METHODS This study is a double-blinded , r and omized clinical trial ( RCT ) that was conducted on 109 children with ASD ( 85 boys and 24 girls ; aged 3 - 10 years ) . The aim of this study was to assess the effects of vitamin D supplementation on the core symptoms of autism in children . ASD patients were r and omized to receive vitamin D3 or placebo for 4 months . The serum levels of 25-hydroxycholecalciferol ( 25 (OH)D ) were measured at the beginning and at the end of the study . The autism severity and social maturity of the children were assessed by the Childhood Autism Rating Scale ( CARS ) , Aberrant Behavior Checklist ( ABC ) , Social Responsiveness Scale ( SRS ) , and the Autism Treatment Evaluation Checklist ( ATEC ) . TRIAL REGISTRATION NUMBER UMIN-CTR Study Design : trial number : UMIN000020281 . RESULTS Supplementation of vitamin D was well tolerated by the ASD children . The daily doses used in the therapy group was 300 IU vitamin D3/kg/day , not to exceed 5,000 IU/day . The autism symptoms of the children improved significantly , following 4-month vitamin D3 supplementation , but not in the placebo group . This study demonstrates the efficacy and tolerability of high doses of vitamin D3 in children with ASD . CONCLUSIONS This study is the first double-blinded RCT proving the efficacy of vitamin D3 in ASD patients . Depending on the parameters measured in the study , oral vitamin D supplementation may safely improve signs and symptoms of ASD and could be recommended for children with ASD . At this stage , this study is a single RCT with a small number of patients , and a great deal of additional wide-scale studies are needed to critically vali date the efficacy of vitamin D in ASD BACKGROUND Persons with limited exposure to ultraviolet B light , including space travelers , may not receive enough vitamin D. Recent studies indicate that optimal serum 25-hydroxyvitamin D [ 25(OH)D ] should be > or = 80 nmol/L. OBJECTIVE This study was design ed to evaluate the effectiveness of 3 doses of vitamin D to raise and maintain 25(OH)D to a concentration > 80 nmol/L in persons with limited ultraviolet B light exposure . DESIGN This was a 5-mo , prospect i ve , r and omized , double-blind study of vitamin D supplementation . It was conducted during winter in Anta rct ica at the McMurdo Station , when ultraviolet B radiation levels are essentially zero . The 55 subjects were r and omly divided into 3 groups for vitamin D supplementation : 2000 IU/d ( n = 18 ) , 1000 IU/d ( n = 19 ) , and 400 IU/d ( n = 18 ) . An additional 7 subjects did not take supplements or took supplements of their own choosing . Blood sample s were collected about every 2 mo during the winter . RESULTS About 5 mo after supplementation started , 25(OH)D increased to 71 + /- 23 nmol/L in the 2000-IU/d group , 63 + /- 25 nmol/L in the 1000-IU/d group , and 57 + /- 15 nmol/L in the 400-IU/d group and decreased to 34 + /- 12 nmol/L in the group not taking supplements . CONCLUSIONS These data will enable us to provide space crews with evidence -based recommendations for vitamin D supplementation . The findings also have implication s for other persons with limited ultraviolet light exposure , including polar workers and the elderly The aim was to assess the effects of resistance training and vitamin D supplementation on physical performance of healthy elderly subjects . Ninety-six subjects , aged 70 years or more with 25 OH vitamin D levels of 16 ng/ml or less , were r and omized to a  resistance training or control group . Trained and control groups were further r and omized to receive in a double blind fashion , vitamin D 400 IU plus 800 mg of calcium per day or calcium alone . Subjects were followed for nine months . Serum 25 OH vitamin D increased from 12.4+/-2.2 to 25.8+/-6.5 ng/ml among subjects supplemented with vitamin D. Trained subjects had significant improvements in quadriceps muscle strength , the short physical performance test and timed up and go . The latter improved more in trained subjects supplemented with vitamin D. At the end of the follow up , gait speed was higher among subjects supplemented with vitamin ( whether trained or not ) than in non-supplemented subjects ( 838+/-147 and 768+/-127 m/12 min , respectively , p=0.02 ) . Romberg ratio was lower among supplemented controls than non-supplemented trained subjects ( 128+/-40 % and 144+/-37 % , respectively , p=0.05 ) . In conclusion , vitamin D supplementation improved gait speed and body sway , and training improved muscle strength OBJECTIVE Epidemiological data suggest low serum 25-hydroxyvitamin D3 ( 25-OH-D3 ) levels are associated with radiological progression of knee osteoarthritis ( OA ) . This study aim ed to assess whether vitamin D supplementation can slow the rate of progression . METHOD A 3-year , double-blind , r and omised , placebo-controlled trial of 474 patients aged over 50 with radiographically evident knee OA comparing  800 IU cholecalciferol daily with placebo . Primary outcome was difference in rate of medial joint space narrowing ( JSN ) . Secondary outcomes included lateral JSN , Kellgren & Lawrence grade , Western Ontario and McMaster Universities Osteoarthritis Index ( WOMAC ) pain , function , stiffness and the Get up and Go test . RESULTS Vitamin D supplementation  increased 25-OH-D3 from an average of 20.7 ( st and ard deviation ( SD ) 8.9 ) μg/L to 30.4 ( SD 7.7 ) μg/L , compared to 20.7 ( SD 8.1 ) μg/L and 20.3 ( SD 8.1 ) μg/L in the placebo group . There was no significant difference in the rate of JSN over 3 years in the medial compartment of the index knee between the treatment group ( average -0.01 mm/year ) and placebo group ( -0.08 mm/year ) , average difference 0.08 mm/year ( 95 % confidence interval ( CI ) [ -0.14 - 0.29 ] , P = 0.49 ) . No significant interaction was found between baseline vitamin D levels and treatment effect . There were no significant differences for any of the secondary outcome measures . CONCLUSION Vitamin D supplementation did not slow the rate of JSN or lead to reduced pain , stiffness or functional loss over a 3-year period . On the basis of these findings we consider that vitamin D supplementation has no role in the management of knee OA CONTEXT Effects of long-term calcium , with or without vitamin D , on  hip bone mineral density ( BMD ) and bone turnover in sunny climates have not been reported . OBJECTIVE The aim was to evaluate the effect of vitamin D added to calcium supplementation on hip dual-energy x-ray absorptiometry BMD and calcium-related analytes . DESIGN , SETTING , AND PARTICIPANTS The study was a 5-yr r and omized , controlled , double-blind trial of 120 community-dwelling women aged 70 - 80 yr . INTERVENTIONS The interventions were 1200 mg/d calcium with placebo vitamin D ( Ca group ) or with 1000 IU/d vitamin D2 ( CaD group ) , or double placebo ( control ) . MAIN OUTCOME MEASURES Hip BMD , plasma 25-hydroxyvitamin D , biomarkers of bone turnover , PTH , and intestinal calcium absorption were measured . RESULTS Hip BMD was preserved in CaD ( -0.17 % ) and Ca ( 0.19 % ) groups but not controls ( -1.27 % ) at yr 1 and maintained in the CaD group only at yr 3 and 5 . The beneficial effects were mainly in those with baseline 25-hydroxyvitamin D levels below the median ( 68 nmol/liter ) . At yr 1 , compared with controls , the Ca and CaD groups had 6.8 and 11.3 % lower plasma alkaline phosphatase , respectively ( P < or=0.02 ) , and 28.7 and 34.5 % lower urinary deoxypyridinoline to creatinine ratio , respectively ( P < or=0.05 ) . At 5 yr , this suppression was maintained only in the CaD group . CaD reduced PTH at 3 and 5 yr cf . controls ( 27.8 and 31.3 % , P < or=0.005 ) in those with baseline PTH levels above the median ( 3.6 pmol/liter ) . Therapy did not affect intestinal calcium absorption at high carrier loads . CONCLUSIONS Addition of vitamin D to calcium has long-term beneficial effects on bone density in elderly women living in a sunny climate , probably mediated by a long-term reduction in bone turnover rate Severe vitamin D deficiency is common among Muslim immigrants . The dose necessary to correct the deficiency and its consequence for bone health are not known for immigrants . The aim was to assess the effect of relatively low dosages of supplemental vitamin D on vitamin D and bone status in Pakistani immigrants . This 1-year-long r and omised double-blinded placebo-controlled intervention with vitamin D3 ( 10 and 20 microg/d ) included girls ( 10.1 - 14.7 years ) , women ( 18.1 - 52.7 years ) and men ( 17.9 - 63.5 years ) of Pakistani origin living in Denmark . The main endpoints were serum 25-hydroxyvitamin D ( S-25OHD ) , parathyroid hormone , bone turnover markers and bone mass . The study showed that supplementation with 10 and 20 microg vitamin D3 per d increased S-25OHD concentrations similarly in vitamin D-deficient Pakistani women ( 4-fold ) , and that 10 microg increased S-25OHD concentrations 2-fold and 20 microg 3-fold in Pakistani men . S-25OHD concentrations increased at 6 months and were stable thereafter . Baseline S-25OHD concentrations tended to be lower in girls and women than in men ; females achieved about 46 nmol/l and men 55 nmol/l after supplementation . Serum intact parathyroid hormone concentrations decreased at 6 months , but there was no significant effect of the intervention on bone turnover markers and dual-energy X-ray absorptiometry measurements of the whole body and lumbar spine Context : Current approaches to antenatal vitamin D supplementation do not account for interindividual differences in 25-hydroxyvitamin D ( 25(OH)D ) response . Objective : We assessed which maternal and environmental characteristics were associated with 25(OH)D after supplementation with cholecalciferol . Design : Within-r and omization-group analysis of participants in the Maternal Vitamin D Osteoporosis Study trial of vitamin D  supplementation in pregnancy . Setting : Hospital antenatal clinics . Participants : A total of 829 pregnant women ( 422 placebo , 407 cholecalciferol ) . At 14 and 34 weeks of gestation , maternal anthropometry , health , and lifestyle were assessed and 25(OH)D measured . Compliance was determined using pill counts at 19 and 34 weeks . Interventions : 1000 IU/d of cholecalciferol or matched placebo from 14 weeks of gestation until delivery . Main Outcome Measure : 25(OH)D at 34 weeks , measured in a single batch ( Diasorin Liaison ) . Results : 25(OH)D at 34 weeks of gestation was higher in the women r and omized to vitamin D ( mean [ SD ] , 67.7 [ 21.3 ] nmol/L ) compared with placebo ( 43.1 [ 22.5 ] nmol/L ; P < .001 ) . In women r and omized to cholecalciferol , higher pregnancy weight gain from 14 to 34 weeks of gestation ( kg ) ( β = −0.81 [ 95 % confidence interval −1.39 , −0.22 ] ) , lower compliance with study medication ( % ) ( β = −0.28 [ −0.072 , −0.48 ] ) , lower early pregnancy 25(OH)D ( nmol/L ) ( β = 0.28 [ 0.16 , 0.40 ] ) , and delivery in the winter vs the summer ( β = −10.5 [ −6.4 , −14.6 ] ) were independently associated with lower 25(OH)D at 34 weeks of gestation . Conclusions : Women who gained more weight during pregnancy had lower 25(OH)D in early pregnancy and delivered in winter achieved a lower 25(OH)D in late pregnancy when supplemented with 1000 IU/d cholecalciferol . Future studies should aim to determine appropriate doses to enable consistent repletion of 25(OH)D during pregnancy Background and Objective : The purpose of the present study is to explore the assessment if the transdermal delivery of vitamin D is feasible . Methods : In 50 female Medical students , this study was conducted . Age , weight and height was taken , a detailed history and clinical examination was performed . Blood was drawn for 25 Hydroxy Vitamin D3 ( 25OHD ) level . Two women had > 30 ng/mL of 25OHD and was excluded from the study . The participants were divided into two groups of 24 in each arm . All participants equivocally agreed not to change their dietary habits and life style till the study was over . The study group of women were asked to apply ; Top-D ( Aloe Vera based- Vitamin D3 ) ( Patency Pending ) was developed at King Fahd Hospital of the University , AlKhobar with each gram of the Top-D cream delivering 5000 IU of vitamin D3 . The second group used 1 gram of Aloe vera gel . The participants had no knowledge to which group they belong . A second blood sample was taken at the end of 3 months and the data was analyzed . Results : The data of 48 women was available for analysis . The average age was 22.58 ± 1.95 years .  The mean pre-treatment 25OHD in the study group was 12.05 ng/Ml ± 6.54 and post-treatment was 37.95 ng/mL ± 6.43 ( P=0.001 , CI<28.582 ) . In control group pre-treatment 25OHD was 11.4 ng/mL ± 3.97 and post-treatment was 10.58ng/mL ± 3.03 . Conclusions : This r and omized control study shows that vitamin D3 can safely be delivered through the dermal route . This route could be exploited in treating vitamin D deficiency Background Symptomatic vitamin D deficiency is associated with slowed growth in children . It is unknown whether vitamin D repletion in children with asymptomatic serum vitamin D deficiency can restore normal growth . Objective We tested the impact of vitamin D-supplementation on serum concentrations of 25-hydroxyvitamin D [ 25(OH)D ] and short-term growth in Mongol children , with very low serum vitamin D levels in winter . Design We conducted two r and omized , double-blind , placebo-controlled trials in urban school age children without clinical signs of rickets . The Supplementation Study was a 6-month intervention with an 800 IU vitamin D3 supplement daily , compared with placebo , in 113 children aged 12–15 years . A second study , the Fortification Study , was a 7-week intervention with 710 ml of whole milk fortified with 300 IU vitamin D3 daily , compared with unfortified milk , in 235 children aged 9–11 years . Results At winter baseline , children had low vitamin D levels , with a mean ( ±SD ) serum 25-hydroxyvitamin D [ 25(OH)D ] concentration of 7.3 ( ±3.9 ) ng/ml in the Supplementation Study and 7.5 ( ±3.8 ) ng/ml in the Fortification Study . The serum levels increased in both vitamin D groups — by 19.8 ( ±5.1 ) ng/ml in the Supplementation Study , and 19.7 ( ±6.1 ) ng/ml in the Fortification Study . Multivariable analysis showed a 0.9 ( ±0.3 SE ) cm greater increase in height in the vitamin-D treated children , compared to placebo treated children , in the 6-month Supplementation Study ( p = 0.003 ) . Although the children in the 7-week Fortification Study intervention arm grew 0.2 ( ±0.1 ) cm more , on average , than placebo children this difference was not statistically significant ( p = 0.2 ) . There were no significant effects of vitamin D supplements on differences in changes in weight or body mass index in either trial . For the Fortification Study , girls gained more weight than boys while taking vitamin D 3 ( p-value for interaction = 0.03 ) , but sex was not an effect modifier of the relationship between vitamin D3 and change in either height or BMI in either trial . Conclusions Correcting vitamin D deficiency in children with very low serum vitamin D levels using 800 IU of vitamin D3 daily for six months increased growth , at least in the short-term , whereas , in a shorter trial of 300 IU of D fortified milk daily for 7 weeks did not Summary The effects of higher than recommended vitamin D doses on bone mineral density ( BMD ) and quality are not known . In this study , higher intakes , in postmenopausal women undergoing weight control over 1 year , had no effect on areal or volumetric BMD but prevented the deterioration in cortical bone geometry . Introduction Studies examining how bone responds to a st and ard dose of vitamin D supplementation have been inconsistent . In addition , the effects of higher doses on BMD and quality are not known . Postmenopausal women undergoing weight control to improve health outcomes are particularly at risk for bone loss and might benefit from supplemental vitamin D intake above the recommended allowance . Methods This 1-year-long , r and omized , double-blind controlled study addresses whether vitamin D supplementation , in healthy overweight/obese older women , affects BMD and bone structural parameters . In addition , bone turnover and serum total , free , and bioavailable 25-hydroxyvitamin D ( 25OHD ) responses to one of three daily levels of vitamin D3 ( 600 , 2000 , 4000 IU ) with 1.2 Ca g/day during weight control were examined . Results Fifty-eight women ( age , 58 ± 6 years ; body mass index , 30.2 ± 3.8 kg/m2 , serum 25OHD , 27.3 ± 4.4 ng/mL ) were r and omized to treatment . After 1 year , serum 25OHD concentrations increased to 26.5 ± 4.4 , 35.9 ± 4.5 , and 41.5 ± 6.9 ng/mL , in groups 600 , 2000 , and 4000 IU , respectively , and differed between groups ( p < 0.01 ) . Weight change was similar between groups ( −3.0 ± 4.1 % ) . Cortical ( Ct ) thickness of the tibia changed by −1.5 ± 5.1 % , + 0.6 ± 3.2 % , and + 2.0 ± 4.5 % in groups 600 , 2000 , and 4000 IU , respectively , and each group was significantly different from each other ( p < 0.05 ) . Conclusion The decline in Ct thickness was prevented with higher vitamin D3 supplementation , but there were no other significant changes due to treatment over 1 year . Whether these findings translate to changes in biomechanical properties leading to reduced fracture risk should be addressed in future studies Summary Daily dosing with vitamin D often fails to achieve optimal outcomes , and it is uncertain what the target level of 25-hydroxyvitamin D should be . This study found that large loading doses of vitamin D3 rapidly and safely normalize 25OHD levels , and that monthly dosing is similarly effective after 3–5 months . With baseline 25OHD > 50 nmol/L , vitamin D supplementation does not reduce PTH levels . Introduction There is concern that vitamin D supplementation doses are frequently inadequate , and that compliance with daily medication is likely to be suboptimal . Methods This r and omized double-blind trial compares responses to three high-dose vitamin D3 regimens and estimates optimal 25-hydroxyvitamin D ( 25OHD ) levels , from changes in parathyroid hormone ( PTH ) , and procollagen type I amino-terminal propeptide ( P1NP ) in relation to baseline 25OHD . Sixty-three elderly participants were r and omized to three regimens of vitamin D supplementation : a 500,000-IU loading dose ; the loading dose plus 50,000 IU/month ; or 50,000 IU/month . Results The Loading and Loading + Monthly groups showed increases in 25OHD of 58 ± 28 nmol/L from baseline to 1 month . Thereafter , levels gradually declined to plateaus of 69 ± 5 nmol/L and 91 ± 4 nmol/l , respectively . In the Monthly group , 25OHD reached a plateau of ~80 ± 20 nmol/L at 3–5 months . There were no changes in serum calcium concentrations . PTH and P1NP were only suppressed by vitamin D treatment in those with baseline 25OHD levels < 50 and < 30 nmol/L , respectively . Conclusions Large loading doses of vitamin D3 rapidly and safely normalize 25OHD levels in the frail elderly . Monthly dosing is similarly effective and safe , but takes 3–5 months for plateau 25OHD levels to be reached In this double blind , unicentre , r and omized , placebo controlled study , we evaluated the changes in 25-hydroxyvitamin D ( 25(OH)D ) serum levels in 150 young Belgian adults ( 18–30 years ) , monthly supplemented with 50,000 IU of vitamin D ( VTD ) or placebo for 6 months , from November 2010 to May 2011 . At T0 , 30 % of the population presented 25(OH)D serum levels below 20 ng/mL. In the VTD-treated group , mean serum levels increased from 21.2 ± 8.2 to 30.6 ± 8.8 ng/mL ( P < 0.001 ) at T3mo and to 36.0 ± 9.2 ng/mL ( P < 0.001 ) at T6mo . Despite documented VTD intake , no changes in serum levels were , however , observed in 10 % of the treated group . In the placebo group , mean 25(OH)D serum levels decreased from 22.8 ± 8.5 to 14.0 ± 6.9 ng/mL at T3mo ( P < 0.001 ) but returned to values not significantly different from those observed at T0 ( 23.5 ± 8.6 ng/mL ) at T6mo . No difference between serum calcium levels was observed between the groups throughout the study . In conclusion , monthly supplementation with 50,000 UI of VTD in winter can warrant serum 25(OH)D levels above 20 ng/mL in 96.2 % of those healthy young adults without inducing unacceptably high 25(OH)D concentration . This supplementation is safe and may be proposed without 25(OH)D testing Vitamin D is hydroxylated in the liver and kidneys to its active form , which can bind to the vitamin D receptor ( VDR ) . The VDR is present in a wide variety of different cells types and tissues and acts as a transcription factor . Although activation of the VDR is estimated to regulate expression of up to 5 % of the human genome , our study is the first analysing gene expression after supplementation in more than 10 subjects . Subjects of a r and omized controlled trial ( RCT ) received either vitamin D3 ( n=47 ) in a weekly dose of 20,000 IU or placebo ( n=47 ) for a period of three to five years . For this study , blood sample s for preparation of RNA were drawn from the subjects and mRNA gene expression in blood was determined using microarray analysis . The two study groups were similar regarding gender , age , BMI and duration of supplementation , whereas the mean serum 25-hydroxyvitamin D ( 25(OH)D ) level as expected was significantly higher in the vitamin D group ( 119 versus 63nmol/L ) . When analysing all subjects , nearly no significant differences in gene expression between the two groups were found . However , when analysing men and women separately , significant effects on gene expression were observed for women . Furthermore , when only including subjects with the highest and lowest serum 25(OH)D levels , additional vitamin D regulated genes were disclosed . Thus , a total of 99 genes ( p≤0.05 , log2 fold change ≥|0.2| ) were found to be regulated , of which 72 have not been published before as influenced by vitamin D. These genes were particularly involved in the interleukin signaling pathway , oxidative stress response , apoptosis signaling pathway and gonadotropin releasing hormone receptor pathway . Thus , our results open the possibility for many future studies Background Bariatric patients often suffer from vitamin D deficiency ( VDD ) , and both , morbid obesity and VDD , are related to non-alcoholic fatty liver disease . However , limited data are available regarding best strategies for treating VDD , particularly , in bariatric patients undergoing omega-loop gastric bypass ( OLGB ) . Therefore , we examined the efficacy and safety of a forced vitamin D dosing regimen and intervention effects in liver fibrotic patients . Methods In this double-blind , r and omized , placebo-controlled trial , 50 vitamin D-deficient patients undergoing OLGB were r and omly assigned to receive , in the first month postoperatively , oral vitamin D3 ( ≤3 doses of 100,000 IU ; intervention group ) or placebo as loading dose ( control group ) with subsequent maintenance dose ( 3420 IU/day ) in both groups until 6-month visit . Results Compared with control group , higher increase of 25(OH)D ( 67.9 ( 21.1 ) vs. 55.7 nmol/L ( 21.1 ) ; p = 0.049 ) with lower prevalence of secondary hyperparathyroidism ( 10 vs. 24 % ; p = 0.045 ) was observed in intervention group . No ( serious ) adverse events related to study medication were found . The loading dose regimen was more effective in increasing 25(OH)D in patients with significant liver fibrosis while this was not the case for conventional supplementation ( placebo with maintenance dose ) ( 71.5 ( 20.5 ) vs. 22.5 nmol/L ( 13.8 ) ; p = 0.022 ; n = 14 ) . Conclusions Our findings indicate that a high vitamin D3 loading dose , in the first month postoperatively , with subsequent maintenance dose is effective and safe in achieving higher vitamin D concentrations in OLGB patients . Unexpectedly , it is more effective in patients with significant liver fibrosis which is of potentially high clinical relevance and requires further investigation OBJECTIVE The objective was to assess the amount of vitamin D3 stored in adipose tissue after long-term supplementation with high dose vitamin D3 . DESIGN A cross-sectional study on 29 subjects with impaired glucose tolerance who had participated in a r and omized controlled trial with vitamin D3 20 000 IU ( 500 μg ) per week vs placebo for 3 - 5 years . METHODS Abdominal subcutaneous fat tissue was obtained by needle biopsy for the measurements of vitamin D3 and 25-hydroxyvitamin D3 ( 25(OH)D3 ) . Body fat was measured with dual-energy X-ray absorptiometry , and serum 25(OH)D3 level was quantified . RESULTS In the subjects given vitamin D3 , the median concentrations of serum 25(OH)D3 , fat vitamin D3 , and fat 25(OH)D3 were 99 nmol/l , 209 ng/g , and 3.8 ng/g , respectively ; and correspondingly in the placebo group 62 nmol/l , 32 ng/g , and 2.5 ng/g . If assuming an equal amount of vitamin D3 stored in all adipose tissue in the body , the median body store was 6.6 mg vitamin D3 and 0.12 mg 25(OH)D3 in those given vitamin D3 . CONCLUSIONS Subcutaneous adipose tissue may store large amounts of vitamin D3 . The clinical importance of this storage needs to be determined Background Vitamin D insufficiency is highly prevalent . Most of the studies concerning vitamin D status were generated from countries situated at temperate latitudes . It is less clear what the extent of vitamin D insufficiency is in countries situated in the tropics and how geographical regions within country would affect vitamin D status . In the present study , we investigated vitamin D status in Thais according to geographical regions and other risk factors . Methods Subjects consisted of 2,641 adults , aged 15 - 98 years , r and omly selected from the Thai 4th National Health Examination Survey ( 2008 - 9 ) cohort .  Serum 25 hydroxyvitamin D  were measured by liquid chromatography/t and em mass spectrometry . Data were expressed as mean ± SE . Results Subjects residing in Bangkok , the capital city of Thail and , had lower 25(OH)D levels than other parts of the country ( Bangkok , central , northern , northeastern and southern regions : 64.8 ± 0.7 , 79.5 ± 1.1 , 81.7 ± 1.2 , 82.2 ± 0.8 and 78.3 ± 1.3 nmol/L , respectively ; p < 0.001 ) . Within each region , except for the northeastern part of the country , subjects living inside municipal areas had lower circulating 25(OH)D ( central , 77.0 ± 20.9 nmol/L vs 85.0 ± 22.1 nmol/L , p < 0.001 ; north 79.3 ± 22.1 nmol/L vs 86.8 ± 21.8 nmol/L , p < 0.001 ; northeast 84.1 ± 23.3 nmol/L vs 87.3 ± 20.9 nmol/L , p = 0.001 ; south , 76.6 ± 20.5 nmol/L vs 85.2 ± 24.7 nmol/L , p < 0.001 ) . Overall , the prevalence of vitamin D insufficiency was 64.6 % , 46.7 % , and 33.5 % in Bangkok , municipal areas except Bangkok , and outside municipal area in other parts of the country , respectively . In addition , the prevalence of vitamin D insufficiency according to geographical regions was 43.1 % , 39.1 % , 34.2 % and 43.8 % in the central , north , northeast and south , respectively . After controlling for covariates in multiple linear regression analysis , the results showed that low serum 25(OH)D levels were associated with being female , younger age , living in urban and Bangkok . Conclusions Vitamin D insufficiency is common and varies across geographical regions in Thail and Objective This study sought to investigate the effects of vitamin D supplementation and aquatic exercise on pulmonary function in postmenopausal women . Material s and methods This prospect i ve and controlled study included 104 women ( 62 ± 6.5 years ) divided into three groups : a control group lacking vitamin D and calcium supplementation which remained sedentary ( CG ; n = 17 ) ; a control group receiving vitamin D and calcium supplementation which remained sedentary ( CDG , n = 33 ) ; and a group that completed aquatic exercises three times a week and received vitamin D and calcium supplementation ( DTG , n = 54 ) . Data before and after 6 months of the study were analyzed , including serum 25-hydroxyvitamin D ( 25(OH)D ) and calcium concentrations , peak expiratory flow ( PEF ) , forced vital capacity ( FVC ) , and cirtometry . Results We observed significant increases in 25(OH)D concentrations in CDG ( 52.9 ± 2.4 to 69.1 ± 2.2 ; nmol/L ; p < 0.0001 ) and DTG groups ( 55.5 ± 3 to 71.5 ± 3 nmol/L ; p < 0.0001 ) . PEF increased by 7 ± 2 % ( p = 0.0080 ) in CDG group and 11 ± 2 % ( p < 0.0001 ) in DTG group , whereas FVC increased by 7 ± 2 % ( p = 0.0016 ) in the CDG group and 10 ± 2 % ( p < 0.0001 ) in the DTG group , whereas CG had no changes in any of these parameters . The increment value of cirtometry in DTG group ( + 43 ± 3 % ) were significantly ( p < 0.0001 ) higher than those in CG ( -4 ± 8 % ) and CDG ( + 4 ± 9 % ) groups . Conclusion Our data suggest that vitamin D supplementation improves pulmonary function parameters in postmenopausal women Objective : Improvement of vitamin D and K status of about 60 -y-old postmenopausal Dutch women . Design : In a r and omized study postmenopausal women with normal ( T-score > −1 ; n=96 ) and low ( T-score≤−1 ; n=45 ) bone mineral density ( BMD ) of the lumbar spine , were supplemented with 350–400 IU vitamin D3 , 80 μg vitamins K1 , vitamins K1+D3 , or placebo for 1 y. Serum 25-hydroxyvitamin D [ 25(OH)D ] and percentage carboxylated osteocalcin ( % carbOC ) were measured at baseline and after 3 , 6 and 12 months . Results : Baseline % carbOC of the entire study population was positively correlated with BMD of the lumbar spine and femoral neck . Correspondingly , women with low BMD had lower % carbOC at baseline than women with normal BMD but this difference disappeared after 1 y of supplementation with vitamin K1 ( ( mean±s.d . ) 68±11 % ( 95 % CI , 64.5–71.2 % ) vs 72±6 % ( 95 % CI , 70.1–72.9 % ) , respectively ) . One year of supplementation with vitamin D3 showed maximum increases in 25(OH)D of 33±29 % ( 95 % CI , 24.8–41.8 % ) and 68±58 % ( 95 % CI , 50.1–84.6 % ) in women with normal and low BMD , respectively . During winter , however , a 29 % decline in maximum 25(OH)D levels was not prevented in women with low BMD . Conclusion : Daily supplementation of Dutch postmenopausal women with > 400 IU vitamin D3 is indicated to prevent a winter decline in 25(OH)D and to control serum parathyroid hormone levels . Daily supplementation with 80 μg vitamin K1 seems to be necessary to reach premenopausal % carbOC levels . A stimulatory effect of calcium and /or vitamin D on % carbOC can not be excluded . European Journal of Clinical Nutrition ( 2000 ) 54 , 626–631 Background Vitamin D deficiency has been associated with multiple diseases , but the causal relevance and underlying processes are not fully understood . Elucidating the mechanisms of action of drug treatments in humans is challenging , but application of functional genomic approaches in r and omized trials may afford an opportunity to systematic ally assess molecular responses . Methods In the Biochemical Efficacy and Safety Trial of Vitamin D ( BEST-D ) , a double-blind , placebo-controlled , dose-finding , r and omized clinical trial , 305 community-dwelling individuals aged over 65 years were r and omly allocated to treatment with vitamin D3 4000 IU , 2000 IU or placebo daily for 12 months . Genome-wide genotypes at baseline , and transcriptome and plasma levels of cytokines ( IFN-γ , IL-10 , IL-8 , IL-6 and TNF-α ) at baseline and after 12 months , were measured . The trial had > 90 % power to detect 1.2-fold changes in gene expression . Findings Allocation to vitamin D for 12-months was associated with 2-fold higher plasma levels of 25-hydroxy-vitamin D ( 25[OH]D , 4000 IU regimen ) , but had no significant effect on whole-blood gene expression ( FDR < 5 % ) or on plasma levels of cytokines compared with placebo . In pre-specified analysis , rs7041 ( intron variant , GC ) had a significant effect on circulating levels of 25(OH)D in the low dose , but not in the placebo or high dose vitamin D regimen . A gene expression quantitative trait locus analysis ( eQTL ) demonstrated evidence of 31,568 cis-eQTLs ( unique SNP-probe pairs ) among individuals at baseline and 34,254 after supplementation for 12 months ( any dose ) . No significant associations involving vitamin D supplementation response eQTLs were found . Interpretation We performed a comprehensive functional genomics and molecular analysis of vitamin D supplementation in a r and omized , placebo-controlled trial . Although this study was limited to mostly Caucasian individuals aged over 65 years , the results differ from many previous studies and do not support a strong effect of vitamin D on long-term transcriptomic changes in blood or on plasma cytokine levels . The trial demonstrates the feasibility of applying functional genomic and genetic approaches in r and omized trials to assess molecular and individual level responses . Key Result Supplementation with high-dose vitamin D in older people for 12 months in a r and omized , placebo-controlled trial had no significant effect on gene expression or on plasma concentrations of selected cytokines . Trial Registration S RCT N registry ( Number 07034656 ) and the European Clinical Trials Data base ( EudraCT Number 2011 - 005763 - 24 ) OBJECTIVE To assess the prevalence of osteoporosis in healthy ambulatory postmenopausal Indian women as measured by dual-energy x-ray absorptiometry and to study the dietary calcium intake and vitamin D status and their influence on bone mineral density ( BMD ) . METHODS We conducted a community-based cross-sectional study in a semiurban region . A r and omized cluster sampling technique was used . The study cohort consisted of 150 ambulatory postmenopausal women ( > or = 50 years old ) .  Dual-energy x-ray absorptiometry for BMD was performed at the lumbar spine and femoral neck . Dietary calcium intake and biochemical variables were assessed . RESULTS The prevalence of osteoporosis was 48 % at the lumbar spine , 16.7 % at the femoral neck , and 50 % at any site . The mean dietary calcium intake was much lower than the recommended intake for this age-group . There was a significant positive correlation between body mass index and BMD at the lumbar spine and the femoral neck ( r = 0.4 ; P = .0001 ) . BMD at the femoral neck was significantly less ( mean , 0.657 versus 0.694 g/cm(2 ) ) in the vitamin D-insufficient study subjects in comparison with the vitamin D-sufficient women ( P = .03 ) . CONCLUSION The high prevalence of osteoporosis and vitamin D insufficiency in this semiurban group of postmenopausal women in India is a major health concern . Measures such as adequate calcium intake and vitamin D supplementation in women of this age-group may be beneficial Scientific data pertaining to vitamin D supplementation during lactation are scarce . The daily recommended intake for vitamin D during lactation has been arbitrarily set at 400 IU/d ( 10 microg/d ) . This recommendation is irrelevant with respect to maintaining the nutritional vitamin D status of mothers and nursing infants , especially among darkly pigmented individuals . Our objective was to examine the effect of high-dose maternal vitamin D2 supplementation on the nutritional vitamin D status  of mothers and nursing infants . Fully lactating women ( n = 18 ) were enrolled at 1 mo after birth to 1 of 2 treatment arms , ie , 1600 IU vitamin D2 and 400 IU vitamin D3 ( prenatal vitamin ) or 3600 IU vitamin D2 and 400 IU vitamin D3 , for a 3-mo study period . High-dose ( 1600 or 3600 IU/d ) vitamin D2 supplementation for a period of 3 mo safely increased circulating 25-hydroxyvitamin D [ 25(OH)D ] concentrations for both groups . The antirachitic activity of milk from mothers receiving 2000 IU/d vitamin D increased by 34.2 IU/L , on average , whereas the activity in the 4000 IU/d group increased by 94.2 IU/L. Nursing infant circulating 25(OH)D2 concentrations reflected maternal intake and the amount contained in the milk . With limited sun exposure , an intake of 400 IU/d vitamin D would not sustain circulating 25(OH)D concentrations and thus would supply only limited amounts of vitamin D to nursing infants in breast milk . A maternal intake of 2000 IU/d vitamin D would elevate circulating 25(OH)D concentrations for both mothers and nursing infants , albeit with limited capacity , especially with respect to nursing infants . A maternal intake of 4000 IU/d could achieve substantial progress toward improving both maternal and neonatal nutritional vitamin D status Background : The Institute of Medicine ( IOM ) dietary guidelines for vitamin D are based on limited pediatric data . Our objective was to estimate the dietary vitamin D requirements for maintaining serum 25-hydroxyvitamin D [ 25(OH)D ] concentrations at the various IOM-considered thresholds of vitamin D status ( 12 , 16 , and 20 ng/ml ) during fall and winter in children . Methods : Ninety-six healthy 8- to 14-y-old Pittsburgh-area black and white children enrolled in a r and omized , placebo-controlled trial of vitamin D3 1,000 IU daily for 6 mo with baseline and 2-mo follow-up assessment s completed during October through April were studied .  Vitamin D intake from diet and study supplement adjusted for adherence and serum 25(OH)D were measured . Results : The  vitamin D intakes needed to maintain serum 25(OH)D concentrations at 12 , 16 , and 20 ng/ml in 90 % of the children were 581 , 1,062 , and 1543 IU/day , respectively . The estimated  vitamin D intakes needed to maintain serum 25(OH)D concentrations at 20 ng/ml in 97.5 % of the children was 2,098 IU/day . Conclusion : Our data suggest that the current vitamin D recommended dietary allowance ( RDA ) ( 600 IU/day ) is insufficient to cover the skeletal health needs of at least 50 % of black and white children Background The high-density lipoprotein cholesterol ( HDL-C ) level has been shown to have a significant role in the prevention of cardiovascular diseases and atherosclerosis . Low vitamin D levels have been shown to be correlated with dyslipidemia , but limited data exist on indigenous children . Objectives We aim ed to investigate the effect of vitamin D supplementation on HDL-C levels in school-aged Iranian children . Methods In this prospect i ve controlled clinical trial , 47 healthy children ( 23 boys ) aged 10 - 14 years , students of Birj and ( Iran ) elementary schools , were selected and r and omly divided into two groups . The study group received a vitamin D supplement ( 1000 mg capsule ) daily for one month , and placebo tablets were prescribed to the controls . Before and after the treatment course , the serum HDL-C and 25-hydroxy vitamin D levels of both groups were measured . The data were analyzed by SPSS , ver . 16 , and Chi-square tests , Fisher ’s exact test , paired- sample t-tests , and Pearson ’s correlation were used , wherever appropriate . The significance level was set at P < 0.05 . Results Forty children completed the study ; their mean age was 11.5 ± 1.175 years .  The mean serum levels of both HDL-C and vitamin D showed a significant rise following the treatment in the study group ( P = 0.007 and P < 0.001 , respectively ) , whereas both variables decreased slightly in the control group ( P = 0.27 ) . There was no statistically significant difference in the mean serum levels of HDL-C and vitamin D between the two groups after the intervention ( P = 0.11 and P = 0.20 , respectively ) . Conclusions Vitamin D supplements seem to have a positive impact on serum HDL-C levels and may be effective in reducing the risk of cardiovascular diseases in the long term Background . Vitamin D deficiency ( VDD ) is a public health concern in adults worldwide . This study aims to explore the extent of VDD and its associated factors among adults in the United Arab Emirates ( UAE ) . Subjects and Methods . Quantitative , cross-sectional research was used to assess VDD and its associated factors in 216 adults recruited from r and omly selected community-based healthcare setting s over a six-month period . Recent values of vitamin D and glycated hemoglobin ( HbA1c ) were abstract ed from medical records , followed by interviews with participants to obtain information on factors related to VDD and other covariates and to measure their heights and weights . Results . A total of 74 % of participants demonstrated VDD ( vitamin D serum level ≤ 30 nmol/L ) . Emirati participants had higher odds of having VDD compared to non-Emiratis ( OR : 2.95 ; 95 % CI : 1.58–5.52 ) , with also significantly increased odds of the condition appearing in older , less educated , and employed adults . Diabetes type 2 ( HbA1c ≥ 6.5 % ) , depression , and obesity were significantly associated with an increased likelihood of VDD  after accounting for other covariates . Conclusion . VDD is a significant problem for UAE adults and requires attention by public health policy makers . Diabetes , obesity , and depression need to be considered when screening for vitamin OBJECTIVE Improve vitamin D status in lactating women and their recipient infants , and measure breast milk calcium concentration [ Ca ] as a function of vitamin D regimen . DESIGN / METHODS Fully breastfeeding mothers were r and omized at 1 month postpartum to 2000 ( n = 12 ) or 4000 ( n = 13 ) IU/day vitamin D for 3 months to achieve optimal vitamin D status [ serum 25(OH)D > or = 32 ng/mL ( 80 nmol/L ) ] . Breast milk [ Ca ] , maternal and infant serum 25(OH)D and serum Ca , and maternal urinary Ca/Cr ratio were measured monthly . RESULTS Mothers were similar between groups for age , race , gestation , and birth weight . 25(OH)D increased from 1 to 4 months in both groups ( mean + /- SD ) : + 11.5 + /- 2.3 ng/mL for group 2000 ( p = 0.002 ) and + 14.4 + /- 3.0 ng/mL for group 4000 ( p = 0.0008 ) . The 4000 IU/day regimen was more effective in raising both maternal and infant serum levels and breast milk antirachitic activity than the 2000 IU/day regimen . Breast milk [ Ca ] fell with continued lactation through 4 months in the 2000 and 4000 IU groups . Decline in breast milk [ Ca ] was not associated with vitamin D dose ( p = 0.73 ) or maternal 25(OH)D ( p = 0.94 ) . No mother or infant experienced vitamin D-related adverse events , and all laboratory parameters remained in the normal range . CONCLUSION High-dose vitamin D was effective in increasing 25(OH)D levels in fully breastfeeding mothers to optimal levels without evidence of toxicity . Breast milk [ Ca ] and its decline in both groups during 1 to 4 months were independent of maternal vitamin D status and regimen . Both the mother and her infant attained improved vitamin D status and maintained normal [ Ca ] Summary There is a huge prevalence of hypovitaminosis D in the Indian population . We studied the efficacy and safety of oral vitamin D supplementation in apparently healthy adult women . Monthly cholecalciferol given orally , 60,000 IU/month during summers and 120,000 IU/month during winters , safely increases 25-hydroxyvitamin D ( 25(OH)D ) levels to near normal levels . Introduction There is a huge burden of hypovitaminosis D in the Indian population . The current recommendation for vitamin D supplementation is not supported by sufficient evidence . Methods Study subjects included 100 healthy adult women of reproductive age group from hospital staff . They were r and omized into group A ( control ) and group B ( supplement ) by simple r and omization . Group B received 60,000 IU of cholecalciferol/month administered orally for 3 months , and then group A received 60,000 IU and group B 120,000 IU/month for 6 months . Results Mean baseline 25(OH)D level was 4.5 ± 3.1 ng/ml and parathyroid hormone level was 50 ± 25 pg/ml . In group B , 25(OH)D levels increased from 4.8 ± 3.5 to 31.6 ± 15.5 ng/ml ( P < 0.001 ) in 3 months . Interestingly , the increase , although of lower magnitude , was also observed in control group A , from 4.5 ± 3.4 ng/ml ( in spring ) to 10.8 ± 7.2 ng/ml ( in summer ; P < 0.001 ) . In group A ( 60,000 IU/month ) , mean 25(OH)D level had increased to 22.3 ± 12.4 ng/ml ( P < 0.001 ) at 9 months ( winter ) . In group B ( 120,000 IU/month ) , 25(OH)D levels were maintained at 30.7 ± 12.8 ng/ml at 9 months ( winter ) . Conclusion Our data show that monthly administration of 60,000 IU cholecalciferol in healthy subjects with hypovitaminosis D may suffice in summer months , but higher doses may be more appropriate during winter months Background : Dark skin and low exposure to sunlight increase the risk of vitamin D insufficiency in children . Objective : The aim of the study was to evaluate the amount of vitamin D needed to ascertain that most children > 4 y of age attain sufficient serum 25-hydroxyvitamin D [ S-25(OH)D ; i.e. , ≥50 nmol/L ] during winter regardless of latitude and skin color . Design : In a longitudinal , double-blind , r and omized , food-based intervention study , 5- to 7-y-old children from northern ( 63 ° N ) and southern ( 55 ° N ) Sweden with fair ( n = 108 ) and dark ( n = 98 ) skin were included . Children , stratified by skin color by using Fitzpatrick 's definition , were r and omly assigned to receive milk-based vitamin D3 supplements that provided 2 ( placebo ) , 10 , or 25 μg/d during 3 winter months . Results : Mean daily vitamin D intake increased from 6 to 17 μg and 26 μg in the intervention groups supplemented with 10 and 25 μg , respectively . In the intention-to-treat analysis , 90.2 % ( 95 % CI : 81.1 % , 99.3 % ) of fair-skinned children r and omly assigned to supplementation of 10 μg/d attained sufficient concentrations , whereas 25 μg/d was needed in dark-skinned children to reach sufficiency in 95.1 % ( 95 % CI : 88.5 % , 100 % ) . In children adherent to the study product , 97 % ( 95 % CI : 91.3 % , 100 % ) and 87.9 % ( 95 % CI : 76.8 % , 99 % ) of fair- and dark-skinned children , respectively , achieved sufficient concentrations if supplemented with 10 μg/d . By using 95 % prediction intervals for 30 and 50 nmol S-25(OH)D/L , intakes of 6 and 20 μg/d are required in fair-skinned children , whereas 14 and 28 μg/d are required in children with dark skin . Conclusion : Children with fair and dark skin require vitamin D intakes of 20 and 28 μg/d , respectively , to maintain S-25(OH)D ≥50 nmol/L , whereas intakes of 6 and 14 μg/d , respectively , are required to maintain concentrations ≥30 nmol/L during winter . This trial was registered at clinical trials.gov as NCT01741324 Importance Evidence suggests that low vitamin D status may increase the risk of cancer . Objective To determine if dietary supplementation with vitamin D3 and calcium reduces the risk of  cancer among older women . Design , Setting , and Participants A 4-year , double-blind , placebo-controlled , population -based r and omized clinical trial in 31 rural counties ( June 24 , 2009 , to August 26 , 2015—the final date of follow-up ) . A total of 2303 healthy postmenopausal women 55 years or older were r and omized , 1156 to the treatment group and 1147 to the placebo group . Duration of treatment was 4 years . Interventions The treatment group ( vitamin D3 + calcium group ) received 2000 IU/d of vitamin D3 and 1500 mg/d of calcium ; the placebo group received identical placebos . Main Outcomes and Measures The primary outcome was the incidence of all-type cancer ( excluding nonmelanoma skin cancers ) , which was evaluated using Kaplan-Meier survival analysis and proportional hazards modeling . Results Among 2303 r and omized women ( mean age , 65.2 years [ SD , 7.0 ] ; mean baseline serum 25-hydroxyvitamin D level , 32.8 ng/mL [ SD , 10.5 ] ) , 2064 ( 90 % ) completed the study . At year 1 , serum 25-hydroxyvitamin D levels were 43.9 ng/mL in the vitamin D3 + calcium group and 31.6 ng/mL in the placebo group . A new diagnosis of cancer was confirmed in 109 participants , 45 ( 3.89 % ) in the vitamin D3 + calcium group and 64 ( 5.58 % ) in the placebo group ( difference , 1.69 % [ 95 % CI , −0.06 % to 3.46 % ] ; P = .06 ) . Kaplan-Meier incidence over 4 years was 0.042 ( 95 % CI , 0.032 to 0.056 ) in the vitamin D3 + calcium group and 0.060 ( 95 % CI , 0.048 to 0.076 ) in the placebo group ; P = .06 . In unadjusted Cox proportional hazards regression , the hazard ratio was 0.70 ( 95 % CI , 0.47 to 1.02 ) . Adverse events potentially related to the study included renal calculi ( 16 participants in the vitamin D3 + calcium group and 10 in the placebo group ) , and elevated serum calcium levels ( 6 in the vitamin D3 + calcium group and 2 in the placebo group ) . Conclusions and Relevance Among healthy postmenopausal older women with a mean baseline serum 25-hydroxyvitamin D level of 32.8 ng/mL , supplementation with vitamin D3 and calcium compared with placebo did not result in a significantly lower risk of all-type cancer at 4 years . Further research is necessary to assess the possible role of vitamin D in cancer prevention . Trial Registration clinical trials.gov Identifier : The purpose of the study was to determine the effect of vitamin D supplementation on bone turnover and bone loss in elderly women . Three hundred forty-eight women , ages 70 yr and older , were r and omized to receive 400 IU vitamin D3 per day ( n = 177 ) or placebo ( n = 171 ) , double-blind , for a period of 2 yr . Main outcome measures were bone mineral density of both hips ( femoral neck and trochanter ) and the distal radius , as well as biochemical markers of bone turnover . The effect of vitamin D supplementation was expressed as the difference in mean ( percentage ) change between the placebo group and the vitamin D group . The measurements were repeated in 283 women after 1 yr and in 248 women after 2 yr . Vitamin D supplementation significantly increased serum 25-hydroxyvitamin D ( 250HD ) ( + 35 nmol/L ) and 1,25-dehydroxyvitamin D [ 1,25-(OH)2D ] ( + 7.0 pmol/L ) levels and urinary calcium/creatinine ratios ( + 0.5 % ) and significantly decreased PTH(1 - 84 ) secretion ( -0.74 pmol/L ) after 1 yr . No effect was found for the parameters of bone turnover . The effect on the bone mineral density of the left femoral neck was + 1.8 % in the first yr , + 0.2 % in the second yr , and + 1.9 % during the whole period ( 95 % confidence interval 0.4 , 3.4 % ) . At the right femoral neck the effects were + 1.5 % , + 1.1 % , and + 2.6 % ( confidence interval 1.1 , 4.0 % ) , respectively . No effect was found at the femoral trochanter and the distal radius . Supplementation with 400 IU vitamin D3 daily in elderly women slightly decreases PTH secretion and increases bone mineral density at the femoral neck Background / Objectives : Middle Eastern female immigrants are at an increased risk of vitamin D deficiency and their response to prescribed vitamin D dosages may not be adequate and affected by other factors . The objectives were to determine vitamin D deficiency and its determinants in Middle Eastern women living in Auckl and , New Zeal and ( Part-I ) , and to determine serum 25-hydroxyvitamin D ( serum-25(OH)D ) response to two prescribed vitamin D dosages ( Part-II ) in this population . Participants / Methods : Women aged ⩾20 ( n=43 ) participated in a cross-sectional pilot study during winter ( Part-I ) . In Part-II , women aged 20–50 years ( n=62 ) participated in a r and omised , double-blind placebo-controlled trial consuming monthly either 50 000 , 100 000 IU vitamin D3 or placebo for 6 months ( winter to summer ) . Results : All women in Part-I and 60 % women in Part-II had serum-25(OH)D<50 nmol/l . Serum-25(OH)D was higher in prescribed vitamin D users than nonusers ( P=0.001 ) and in Iranians than Arab women ( P=0.001 ; Part-I ) . Mean ( s.d . ) serum-25(OH)D increased in all groups ( time effect , P<0.001 ) and differed between groups ( time × dosage interaction , P<0.001 ; 50 000 IU : from 44.0±16.0 to 70.0±15.0 nmol/l ; 100 000 IU : 48.0±11.0 to 82.0±17.0 nmol/l ; placebo : 45.0±18.0 to 54.0±18.0 nmol/l ) . Only 32 % and 67 % achieved serum-25(OH)D⩾75 nmol/l with 50 000 and 100 000 IU/month , respectively . Predictors of 6-month change in serum-25(OH)D were dose ( B-coefficient±s.e . ; 14.1±2.4 , P<0.001 ) , baseline serum-25(OH)D ( −0.6±0.1 , P<0.001 ) and body fat percentage ( −0.7±0.3 , P=0.01 ) . Conclusions : Vitamin D deficiency/insufficiency is highly prevalent in this population . Monthly 100 000 IU vitamin D for 6 months is more effective than 50 000 IU in achieving serum-25(OH)D ⩾75 nmol/l ; however , a third of women still did not achieve these levels The purpose of this 6-month r and omized , placebo-controlled trial was to determine the effect of season-long ( September-March ) vitamin D supplementation on changes in vitamin D status , which is measured as 25(OH ) D , body composition , inflammation , and frequency of illness and injury . Forty-five male and female athletes were r and omized to 4,000 IU vitamin D ( n = 23 ) or placebo ( n = 22 ) . Bone turnover markers ( NTx and BSAP ) , 25(OH)D , and inflammatory cytokines ( TNF-alpha , IL-6 , and IL1-β ) were measured at baseline , midpoint , and endpoint . Body composition was assessed by DXA and injury and illness data were collected . All athletes had sufficient 25(OH)D ( > 32 ng/ml ) at baseline ( mean : 57 ng/ml ) . At midpoint and endpoint , 13 % and 16 % of the total sample had 25(OH)D < 32 ng/ml , respectively . 25(OH)D was not positively correlated with bone mineral density ( BMD ) in the total body , proximal dual femur , or lumbar spine . In men , total body ( p = .04 ) and trunk ( p = .04 ) mineral-free lean mass ( MFL ) were positively correlated with 25(OH)D. In women , right femoral neck BMD ( p = .02 ) was positively correlated with 25(OH)D. 25(OH)D did not correlate with changes in bone turnover markers or inflammatory cytokines . Illness ( n = 1 ) and injury ( n = 13 ) were not related to 25(OH)D ; however , 77 % of injuries coincided with decreases in 25(OH)D. Our data suggests that 4,000 IU vitamin D supplementation is an inexpensive intervention that effectively increased 25(OH)D , which was positively correlated to bone measures in the proximal dual femur and MFL . Future studies with larger sample sizes and improved supplement compliance are needed to exp and our underst and ing of the effects of vitamin D supplementation in athletes Sarcopenia and osteoporosis represent a growing public health problem . We studied the potential benefit of whole-body vibration ( WBV ) training given a conventional or a high dose of daily vitamin D supplementation in improving strength , muscle mass , and bone density in postmenopausal women . In a 2 × 2 factorial- design trial , 113 institutionalized elderly females aged over 70 years ( mean age 79.6 years ) were r and omly assigned either to a WBV or a no-training group , receiving either a conventional dose ( 880 IU/day ) or a high dose ( 1600 IU/day ) of vitamin D(3 ) . The primary aim was to determine the effects of 6 months of WBV and /or vitamin D supplementation on isometric and dynamic strength , leg muscle mass , and hip bone mineral density ( BMD ) . Additionally , the increase in 25-hydroxyvitamin D [ 25(OH)D ] levels between conventional and high-dose supplementation was compared . After 6 months of treatment , dynamic muscle strength , hip BMD , and vitamin D serum levels improved significantly in all groups , whereas isometric strength and muscle mass did not change . When compared with no training , the WBV program did not result in additional improvements . When compared with 880 IU , a high dose of 1600 IU of vitamin D did result in higher serum vitamin D levels but did not result in additional improvements . In institutionalized women older than 70 years , the WBV training protocol tested is not more efficient in enhancing muscle mass , strength , and hip BMD compared with vitamin D supplementation . A higher dose of 1600 IU of vitamin D does not provide additional musculoskeletal benefit in this population compared with conventional doses Vitamin D status is conventionally defined by the serum concentration of 25-hydroxyvitamin D. However , it has been proposed that the serum cholecalciferol concentration ( D3 ) also determines functional vitamin D sufficiency . The objective of this study was to describe the effect of weekly high-dose vitamin D3 supplementation on inter-dose serum D3 in pregnant women . We conducted a sub- study of a completed r and omized double-blind placebo-controlled trial of vitamin D3 ( 35,000 IU/week ) supplementation in late pregnancy ( AViDD trial ) in Dhaka , Bangladesh . This study included pregnant women enrolled at 26 - 29 weeks gestation who fully adhered to the prenatal supplement intervention for ≥8 consecutive weeks and for whom serum sample s were available for D3 analysis ( n=65 ) . Serum D3 was uniformly low at enrolment . Mean D3 increased and was maximal at 1 day after vitamin D dose administration ( 152.09nmol/L , SD 25.11nmol/L ) and remained significantly higher in VitD vs. Pl at 7 days ( 29.59nmol/L vs. 1.92nmol/L , p=0.007 ) . Daily average of the group mean D3 during the week following dosing was 66.97nmol/L in VitD versus 2.13nmol/L in Pl . In conclusion , serum D3 remained significantly elevated throughout the week following ≥8 consecutive weekly doses of 35,000 IU D3 in pregnant women . However , the clinical ly significant minimum threshold of serum D3 remains to be established Aim : To compare the effect of two different doses ( 500 and 1000 IU/day ) of oral vitamin D3 ( cholecalciferol ) on serum 25-hydroxy vitamin D [ 25(OH)D ] levels in apparently healthy postmenopausal Indian women . Material s and Methods : Serum 25(OH)D , calcium with albumin , phosphorus , and alkaline phosphatase were measured in 92 apparently healthy postmenopausal women . The subjects were r and omly assigned to one of the three groups and received supplementation for 3 months each . Each group received 1000 mg calcium carbonate daily while groups B and C received 500 and 1000 IU of cholecalciferol in addition , respectively . The tests were repeated after 3 months . Results : At baseline , 83.7 % subjects had vitamin D deficiency ( ≤20 ng/mL ) . The difference in the percentage change in mean serum 25(OH)D levels from baseline in group A ( –30.5 ± 5.3 % ) , group B ( + 8.9 ± 19.7 % ) , and in group C ( + 97.8 ± 53.3 % ) was statistically significant ( P < 0.001 ) between the three groups . Serum 25(OH)D level > 20 ng/mL was achieved in 4.7 % ( 1/21 ) , 16 % ( 4/25 ) , and 66.67 % ( 12/18 ) subjects in groups A , B , and C , respectively . No significant change was found in serum calcium , phosphorus , and alkaline phosphatase levels at 3 months in either of the groups from baseline . Conclusions : St and ard dose of cholecalciferol available in “ calcium tablets ” ( 250 IU per 500 mg calcium carbonate ) is not adequate for achieving optimum serum 25(OH)D levels in Indian postmenopausal women . Higher dose of vitamin D supplementation with 1000 IU/day ( 500 IU per 500 mg calcium carbonate ) daily is superior to the st and ard dose therapy . For achievement of optimum serum 25(OH)D levels ( > 30 ng/mL ) in Indian postmenopausal women , still higher doses of vitamin D are likely to be required Objective : Vitamin D supplementation may be required for certain subgroups in the United States in whom status and intake are inadequate , but the impact of various doses , and whether calcium administration jointly or independently influences vitamin D metabolite levels , is unclear . Methods : In a pilot chemoprevention trial of biomarkers of risk for colorectal adenoma , we measured the impact of vitamin D supplementation and /or calcium supplementation on plasma vitamin D metabolite concentrations . Ninety-two adult men and women living in the southeastern United States were r and omized to 800 IU vitamin D3 , 2000 mg elemental calcium , both , or placebo daily for 6 months . We examined vitamin D status at baseline and postintervention and compared the change in plasma 25-hydroxyvitamin D ( 25(OH)D ) and 1,25(OH)2D levels by intervention group using general linear models . Results : Eighty-two percent of the study population had insufficient plasma 25(OH)D concentrations ( < 75 nmol/L ) at baseline , with the lowest levels observed among African American participants . Vitamin D supplements , with or without calcium supplementation , raised plasma 25(OH)D concentrations , on average , by 25 to 26 nmol/L. Half of the study participants were classified as having sufficient 25(OH)D status after 6 months of 800 IU of vitamin D3 daily . Calcium alone did not influence 25(OH)D concentrations . Conclusion : In this southeastern U.S. population , half of the study participants receiving 800 IU vitamin D3 daily had blood 25(OH)D concentrations of ≤75 nmol/L after a 6-month intervention period , supporting higher vitamin D dose requirements estimated by some groups . More research is needed to identify the optimal vitamin D dose to improve 25(OH)D status in various at-risk population OBJECTIVES To determine whether relative vitamin D deficiency during the winter months contributes to age-related bone loss  and whether rates of change in hard- and soft-tissue mass vary during the year . DESIGN Double-blind , placebo-controlled , 1-year trial in 249 women in which equal numbers of women were r and omized to either placebo or 400 IU of vitamin D daily . All women received 377 mg/d of supplemental calcium largely as calcium citrate malate . PATIENTS Healthy , ambulatory postmenopausal women with usual intakes of vitamin D of 100 IU/d . MEASUREMENTS Duplicate spine and whole-body scans were done by dual energy x-ray absorptiometry at 6-month intervals that were timed to periods when 25-hydroxyvitamin D levels were highest and lowest . Period 1 was June-July to December-January and period 2 was December-January to the next June-July . Serum parathyroid hormone and plasma 25-hydroxyvitamin D levels were measured during periods 1 and 2 . MAIN RESULTS In the placebo group , spinal bone mineral density increased in period 1 , decreased in period 2 , and sustained no net change . Women treated with vitamin D had a similar spinal increase in period 1 ( 1.46 % compared with 1.40 % in placebo ) , less loss in period 2 ( -0.54 % compared with -1.22 % , CI for the difference , 0.05 % to 1.31 % , P = 0.032 ) and a significant overall benefit ( 0.85 % compared with 0.15 % , CI for the difference , 0.03 % to 1.37 % , P = 0.04 ) . In period 2 , 25-hydroxyvitamin D levels were lower and parathyroid hormone levels were higher in the placebo than in the vitamin D group . Whole-body lean and fat tissue and bone mineral density varied during the year but did not change overall . CONCLUSIONS At latitude 42 degrees , healthy postmenopausal women with vitamin D intakes of 100 IU daily can significantly reduce late wintertime bone loss and improve net bone density of the spine over one year by increasing their intake of vitamin D to 500 IU daily . A long-term benefit of preventing vitamin D insufficiency in the winter seems likely although it remains to be shown . Observed changes in bone as well as in fat and lean tissue appear to be related to season BACKGROUND AND OBJECTIVES Vitamin D3 ( cholecalciferol ) dose required to maintain sufficiency in non- Caucasian women with postmenopausal osteoporosis ( PMO ) inthe tropics has not been well studied . Some guidelines m and ate 800 - 1000 IU vitamin D/day but the Endocrine Society ( US ) advocates 1500 - 2000 IU/day to maintain 25-hydroxyvitamin-D ( 25(OH)D ) concentration at > 75 nmol/L. We aim ed to establish oral cholecalciferol dose required to maintain 25(OH)D concentration at > 75 nmol/L in PMO Chinese Malaysian women , postulating lower dose requirements amongst light-skinned subjects in the tropics . METHODS AND STUDY DESIGN 90 Chinese Malaysian PMO women in Kuala Lumpur , Malaysia ( 2 ° 30'N ) with baseline serum 25(OH)D levels > = 50 nmol/L were recruited . Prior vitamin D supplements were discontinued and subjects r and omized to oral cholecalciferol 25,000 IU/4-weekly ( Group-A ) or 50,000 IU/4-weekly ( Group- B ) for 16 weeks , administered under direct observation . Serum 25(OH)D , PTH , serum/urinary calcium were measured at baseline , 8 and 16 weeks . RESULTS Baseline characteristics , including osteoporosis severity , sun exposure ( ~3 hours/week ) , and serum 25(OH)D did not differ between treatment arms . After 16 weeks , 91 % of women sufficient at baseline , remained sufficient on 25,000 IU/4-weekly compared with 97 % on 50,000 IU/4-weekly with mean serum 25(OH)D 108.1±20.4 and 114.7±18.4 SD nmol/L respectively ( p=0.273 ) . At trial 's end , 39 % and 80 % of insufficient women at baseline attained sufficiency in Group A and Group B ( p=0.057 ) . Neither dose was associated with hyperparathyroidism or toxicity . CONCLUSIONS Despite pretrial vitamin D supplementation and adequate sun exposure , 25.6 % Chinese Malaysian PMO women were vitamin D insufficient indicating sunshine alone can not ensure sufficiency in the tropics . Both ~900 IU/day and ~1800 IU/day cholecalciferol can safely maintain vitamin D sufficiency in > 90 % of Chinese Malaysian PMO women . Higher doses are required with baseline concentration < 75 AIMS Vitamin D deficiency may increase the risk for type 2 diabetes . African Americans tend to have poor vitamin D status and increased risk of diabetes , but effects of vitamin D supplementation on components of diabetes risk have not been tested in this group . This study was conducted to determine whether vitamin D supplementation improves insulin secretion , insulin sensitivity and glycaemia in African Americans with prediabetes or early diabetes . METHODS In this r and omized , placebo-controlled trial , we examined the effect of 4000 IU/day vitamin D(3 , ) on glycaemia and contributing measures including insulin secretion , insulin sensitivity and the disposition index over 12 weeks in 89 overweight or obese African Americans with prediabetes or early diabetes . Outcome measures were derived from oral glucose tolerance testing . RESULTS Mean plasma 25-hydroxyvitamin D was about 40 nmol/l in the placebo and vitamin D groups at baseline and increased to 81 nmol/l with supplementation . Insulin sensitivity decreased by 4 % in the vitamin D group compared with a 12 % increase in the placebo group ( p = 0.034 ) . Insulin secretion increased by 12 % in the vitamin D group compared with a 2 % increase in the placebo group ( p = 0.024 ) , but changes in the disposition index were similar across groups . There was no effect of supplementation on post-load glucose or other measures of glycaemia . CONCLUSIONS Supplementation with 4000 IU/day vitamin D(3 ) successfully corrected vitamin D insufficiency and had divergent effects on insulin secretion and sensitivity with no overall effect on disposition index or glycaemia . In this study , vitamin D supplementation for 3 months did not change the pathophysiology of prediabetes in overweight and obese African Americans Although there have been several studies of the effect of vitamin D status on bone turnover in the elderly , the findings are unclear , and , furthermore , to date very few have investigated this in young adults . The objective of these r and omized , placebo-controlled , double-blind , 2-center intervention studies was to investigate the effect of cholecalciferol supplementation ( 0 , 5 , 10 , and 15 microg cholecalciferol/d ) throughout winter time on indices of vitamin D status and bone turnover in young ( aged 20 - 40 y ; n = 215 ) and elderly ( aged > or = 64 y ; n = 204 ) adults , with relatively high mean calcium intakes of 976 and 874 mg/d , respectively .  Fasting serum concentrations of 25-hydroxyvitamin D [ 25(OH)D ] , parathyroid hormone ( PTH ) , osteocalcin , bone-specific alkaline phosphatase , and carboxyterminal collagen crosslinks were measured by enzyme immunoassays at baseline and endpoint . Fok I and Taq I vitamin D receptor ( VDR ) genotypes were determined by real-time PCR . Endpoint serum 25(OH)D increased ( P < 0.0001 ) in a dose-related manner with increasing supplemental cholecalciferol ( up to 15 microg/d ) in 20 - 40-y olds and up to 10 microg/d in > or = 64-y olds . Endpoint serum PTH was lower ( P < 0.05 ) in the 3 cholecalciferol-supplemented groups compared with that in the placebo group in > or = 64-y olds , but cholecalciferol supplementation did not affect other markers in either cohort and there was no significant interaction with VDR genotype . In conclusion , cholecalciferol supplementation alone throughout winter did not affect bone turnover markers in apparently healthy young and elderly adults , even when stratified by VDR genotype Background : Evidence for the effects of exercise and vitamin D supplementation on quality of life ( QoL ) , fear of falling ( FoF ) and mental wellbeing in older adults is conflicting . Objective : To study the effects of vitamin D supplementation and multimodal group exercise on psychosocial functions of wellbeing , including QoL , mental wellbeing and FoF. Method : This is a 2-year , double-blind , placebo-controlled vitamin D and open exercise intervention trial with 409 older Finnish women ( 70 - 80 years of age ) r and omized to 4 treatment arms : ( 1 ) placebo without exercise , ( 2 ) vitamin D ( 800 IU/day ) without exercise , ( 3 ) placebo and exercise , and ( 4 ) vitamin D ( 800 IU/day ) with exercise . Exercisers participated in group exercise twice per week for 12 months and once per week for the subsequent 12 months , plus home exercises . Results : When comparing with the placebo without exercise group , there were no statistically significant differences between groups receiving either vitamin D , exercise or both treatments for changes in QoL or mental wellbeing ( although a slight decline was seen in mental wellbeing in those receiving vitamin D only , p = 0.044 ) . The initial slight reduction in FoF was significant in all intervention groups compared with controls ( p < 0.05 ) , but this was only temporary . Conclusion : Neither vitamin D nor exercise contributes to better QoL , FoF or mental wellbeing in community-dwelling healthy older women with sufficient vitamin D levels Summary In 242 community-dwelling seniors , supplementation with either 1000 mg of calcium or 1000 mg of calcium plus vitamin D result ed in a decrease in the number of subjects with first falls of 27 % at month 12 and 39 % at month 20 . Additionally , parameters of muscle function improved significantly . Introduction The efficacy of vitamin D and calcium supplementation on risk of falling in the elderly is discussed controversially . R and omized controlled trials using falls as primary outcome are needed . We investigated long-term effects of calcium and vitamin D on falls and parameters of muscle function in community-dwelling elderly women and men . Methods Our study population consisted of 242 individuals recruited by advertisements and mailing lists ( mean [ ± SD ] age , 77 ± 4 years ) . All serum 25-hydroxyvitamin D ( 25[OH]D ) levels were below 78 nmol/l . Individuals received in a double blinded fashion either 1000 mg of calcium or 1000 mg of calcium plus 800 IU of vitamin D per day over a treatment period of 12 months , which was followed by a treatment-free but still blinded observation period of 8 months . Falls were documented using diaries . The study took place in Bad Pyrmont , Germany ( latitude 52 ° ) and Graz , Austria ( latitude 46 ° ) . Results Compared to calcium mono , supplementation with calcium plus vitamin D result ed in a significant decrease in the number of subjects with first falls of 27 % at month 12 ( RR = 0.73 ; CI = 0.54–0.96 ) and 39 % at month 20 ( RR = 0.61 ; CI = 0.34–0.76 ) . Concerning secondary endpoints , we observed significant improvements in quadriceps strength of 8 % , a decrease in body sway of 28 % , and a decrease in time needed to perform the TUG test of 11 % . Discussion Combined calcium and vitamin D supplementation proved superior to calcium alone in reducing the number of falls and improving muscle function in community-dwelling older individuals AIMS Vitamin D deficiency is considered as a risk factor in cardiometabolic disorders , including cardiovascular diseases , hypertension and Type 2 diabetes mellitus . We have investigated the effect of vitamin D3 supplementation on glucose homeostasis in healthy overweight and obese women . METHODS In a double-blind r and omized placebo-controlled clinical trial , 77 healthy overweight or obese women ( mean age 38 ± 8 years ; BMI 29.9 ± 4.2 kg/m(2 ) ) were r and omly assigned to the vitamin D3 group ( 25 μg/day as cholecalciferol tablets ) or the placebo group  . Selected anthropometric indices , glucose , insulin , HbA(1c ) and homeostasis model assessment of insulin resistance at baseline and after 12 weeks were measured . Dietary intakes using 24-h food recall and food frequency question naires were assessed . Physical activity was assessed by the International Physical Activity Question naire . Adjusted mean differences were calculated using analysis of covariance . Correlation coefficients were calculated by Pearson 's analysis . RESULTS Mean fasting blood glucose concentrations declined in the vitamin D3 and placebo groups ( -0.28 ± 0.4 vs. -0.65 ± 0.4 mmol/l , P < 0.001 ) and the mean percentage of HbA(1c ) was decreased ( -13 ± 18 vs. -19 ± 17 mmol/l , P = 0.06 ) in both groups , respectively . Mean 25-hydroxyvitamin D concentrations increased in the vitamin D3 and placebo groups ( 38.2 ± 32 vs. 4.6 ± 14 nmol/l , P < 0.001 ) , respectively . There was a significant correlation between HbA(1c ) and 25-hydroxyvitamin D concentrations ( r = -0.271 ; P = 0.018 ) . CONCLUSIONS The results indicate that the vitamin D3 supplement of 25 μg/day had no beneficial effect on glycaemic indices in healthy overweight or obese women CONTEXT R and omized control trials ( RCT ) of the effect of vitamin D/calcium supplementation on skeletal muscle strength have not shown promising effect in the elderly . OBJECTIVE Our objective was to assess the effect of vitamin D and /or calcium on muscle strength in young adults with vitamin D deficiency . DESIGN AND SETTING We conducted a RCT using a factorial design at a tertiary-care center from September 2010 to April 2011 . SUBJECTS A total of 173 healthy females with mean age , body mass index , and 25-hydroxyvitamin D [ 25(OH)D ] of 21.7 ± 4.4 yr , 20.8 ± 2.96 kg/m(2 ) , and 9.3 ± 3.37 ng/ml , respectively , were block r and omized to 1 ) double placebo , 2 ) calcium/placebo , 3 ) cholecalciferol/placebo , and 4 ) cholecalciferol/calcium for 6 months . Cholecalciferol was given at 60,000 IU/wk for 8 wk followed by 60,000 IU/fortnight . Elemental calcium was given in doses of 500 mg twice per day for 6 months . METHODS Assessment included h and grip ( primary outcome ) and pinch grip strength , distance walked in 6 min , dyspnea score , quality of life by Short Form ( 36 ) Health Survey ( SP-36 ) , serum 25(OH)D , 1,25-dihydroxyvitamin D , and intact PTH . RESULTS The serum 25(OH)D increased significantly to 29.9 ± 8.35 and 27.0 ± 9.54 ng/ml in two groups on cholecalciferol . The mean h and grip strength ( 19.4 ± 3.92 , 21.1 ± 3.31 , 20.6 ± 3.92 , and 20.1 ± 4.00 kg ) and its increase from baseline ( 0.3 ± 2.25 , 0.3 ± 2.64 , -0.3 ± 2.41 , and 0.6 ± 2.30 kg ) were comparable in four groups at 6 months . Quality of life , urinary calcium/creatinine ratio , and adverse effects were also comparable in groups . CONCLUSION Oral cholecalciferol/calcium supplementation in the dose/schedule used is effective and safe in increasing and maintaining serum 25(OH)D. However , this does not lead to improved skeletal muscle strength in young females CONTEXT Dosages of vitamin D necessary to prevent or treat vitamin D deficiency in children remain to be clarified . OBJECTIVE To determine the effects of vitamin D3 1000 IU/d on serum 25-hydroxyvitamin D [ 25(OH)D ] , PTH , and markers of bone turnover ( osteocalcin and collagen type 1 cross-linked C-telopeptide ) in black children and white children , and to explore whether there is a threshold level of 25(OH)D associated with maximal suppression of serum PTH concentration . DESIGN Healthy 8- to 14-year-old Pittsburgh-area black ( n = 84 ) and white ( n = 73 ) children not receiving vitamin supplements , enrolled from October through March from 2008 through 2011 , were r and omized to vitamin D3 1000 IU or placebo daily for 6 months . RESULTS The mean baseline concentration of 25(OH)D was < 20 ng/mL in both the vitamin D-supplemented group and the placebo group ( 19.8 ± 7.6 and 18.8 ± 6.9 ng/mL , respectively ) . The mean concentration was higher in the supplemented group than in the placebo group at 2 months ( 26.4 ± 8.1 vs 18.9 ± 8.1 ng/mL ; P < .0001 ) and also at 6 months ( 26.7 ± 7.6 vs 22.4 ± 7.3 ; P = .003 ) , after adjusting for baseline 25(OH)D , race , gender , pubertal status , dietary vitamin D intake , body mass index , and sunlight exposure . Increases were only significant in black children , when examined by race . The association between 25(OH)D and PTH concentrations was inverse and linear , without evidence of a plateau . Overall , vitamin D supplementation had no effect on PTH and bone turnover  . CONCLUSIONS Vitamin D3 supplementation with 1000 IU/d in children with mean baseline 25(OH)D concentration < 20 ng/mL effectively raised their mean 25(OH)D concentration to ≥20 ng/mL but failed to reach 30 ng/mL.  Vitamin D supplementation had no effect on PTH concentrations BACKGROUND Vitamin D deficiency is associated with obesity ; whether repletion supports weight loss and changes obesity-related biomarkers is unknown . OBJECTIVE We compared 12 mo of vitamin D3 supplementation with placebo  on weight , body composition , insulin , and C-reactive protein ( CRP ) in postmenopausal women in a weight-loss intervention . DESIGN A total of 218 overweight/obese women ( 50 - 75 y of age ) with serum 25-hydroxyvitamin D [ 25(OH)D ] ≥10 ng/mL but < 32 ng/mL were r and omly assigned to weight loss + 2000 IU oral vitamin D3/d or weight loss + daily placebo . The weight-loss intervention included a reduced-calorie diet ( 10 % weight loss goal ) and 225 min/wk of moderate-to-vigorous aerobic activity . Mean 12-mo changes in weight , body composition , serum insulin , CRP , and 25(OH)D were compared between groups ( intent-to-treat ) by using generalized estimating equations . RESULTS A total of 86 % of participants completed the 12-mo measurements . The mean ( 95 % CI ) change in 25(OH)D was 13.6 ( 11.6 , 15.4 ) ng/mL in the vitamin D3 arm compared with -1.3 ( -2.6 , -0.3 ) ng/mL in the placebo arm ( P < 0.0001 ) . Changes in weight [ -7.1 ( -8.7 , -5.7 ) compared with -7.4 ( -8.1 , -5.4 ) kg ] , body mass index ( in kg/m(2 ) : both -2.8 ) , waist circumference [ -4.9 ( -6.7 , -2.9 ) compared with -4.5 ( -5.6 , -2.6 ) cm ] , percentage body fat [ -4.1 ( -4.9 , -2.9 ) compared with -3.5 ( -4.5 , -2.5 ) ] , trunk fat [ -4.1 ( -4.7 , -3.0 ) compared with -3.7 ( -4.3 , -2.9 ) kg ] , insulin [ -2.5 ( -3.4 , -1.7 ) compared with -2.4 ( -3.3 , -1.4 ) μU/mL ] , and CRP [ -0.9 ( -1.2 , -0.6 ) compared with -0.79 ( -0.9 , -0.4 ) mg/L ] [ corrected ] were similar between groups ( all P > 0.05 ) . Compared with women who achieved 25(OH)D < 32 ng/mL , women r and omly assigned to vitamin D who became replete ( ie , 25(OH)D ≥32 ng/mL ) lost more weight [ -8.8 ( -11.1 , -6.9 ) compared with -5.6 ( -7.2 , -5.0 ) kg ; P = 0.05 ] , waist circumference [ -6.6 ( -9.3 , -4.3 ) compared with -2.5 ( -4.6 , -2.0 ) cm ; P = 0.02 ] , and percentage body fat [ -4.7 ( -6.1 , -3.5 ) compared with -2.6 ( -3.9 , -2.2 ) ; P = 0.04 ] . Among women with complete pill counts ( 97 % adherence ) , the mean decrease in CRP was 1.18 mg/mL ( 46 % ) in the vitamin D arm compared with 0.46 mg/mL ( 25 % ) in the placebo arm ( P = 0.03 ) . CONCLUSIONS Vitamin D3 supplementation  during weight loss did not increase weight loss or associated factors compared with placebo ; however , women who became replete experienced greater improvements . This trial was registered at clinical trials.gov as NCT01240213 Background Vitamin D deficiency is common in the general public and athletic population s and may impair skeletal muscle function . We therefore assessed the effects of vitamin D3 supplementation on serum 25[OH]D concentrations and physical performance . Methods 30 club-level athletes were block r and omised ( using baseline 25[OH]D concentrations ) into one of three groups receiving either a placebo ( PLB ) , 20 000 or 40 000 IU/week oral vitamin D3 for 12 weeks . Serum 25[OH]D and muscle function ( 1-RM bench press and leg press and vertical jump height ) were measured presupplementation , 6 and 12 weeks postsupplementation . Vitamin D deficiency was defined in accordance with the US Institute of Medicine guideline ( < 50 nmol/l ) . Results 57 % of the subject population were vitamin D deficient at baseline ( mean±SD value 51±24 nmol/l ) . Following 6 and 12 weeks supplementation with 20 000 IU ( 79±14 and 85±10 nmol/l , respectively ) or 40 000 IU vitamin D3 ( 98±14 and 91±24 nmol/l , respectively ) , serum vitamin D concentrations increased in all participants , with every individual achieving concentrations greater than 50 nmol/l . In contrast , vitamin D concentration in the PLB group decreased at 6 and 12 weeks ( 37±18 and 41±22 nmol/l , respectively ) . Increasing serum 25[OH]D had no significant effect on any physical performance parameter ( p>0.05 ) . Conclusions Both 20 000 and 40 000 IU vitamin D3 supplementation over a 6-week period elevates serum 25[OH]D concentrations above 50 nmol/l , but neither dose given for 12 weeks improved our chosen measures of physical performance The risk of vitamin D insufficiency is increased in persons having limited sunlight exposure and dietary vitamin D. Supplementation compliance might be improved with larger doses taken less often , but this may increase the potential for side effects . The objective of the present study was to determine whether a weekly or weekly/monthly regimen of vitamin D supplementation is as effective as daily supplementation without increasing the risk of side effects . Participants were forty-eight healthy adults who were r and omly assigned for 3 months to placebo or one of three supplementation regimens : 50 μg/d ( 2000 IU/d , analysed dose 70 μg/d ) , 250 μg/week ( 10 000 IU/week , analysed dose 331 μg/week ) or 1250 μg/week ( 50 000 IU/week , analysed dose 1544 μg/week ) for 4 weeks and then 1250 μg/ month for 2 months . Daily and weekly doses were equally effective at increasing serum 25-hydroxyvitamin D , which was significantly greater than baseline in all the supplemented groups after 30 d of treatment . Subjects in the 1250 μg treatment group , who had a BMI > 26 kg/m2 , had a steady increase in urinary Ca in the first 3 weeks of supplementation , and , overall , the relative risk of hypercalciuria was higher in the 1250 μg group than in the placebo group ( P=0·01 ) . Although vitamin D supplementation remains a controversial issue , these data document that supplementing with ≤ 250 mg/week ( ≤ 10 000 IU/week ) can improve or maintain vitamin D status in healthy population s without the risk of hypercalciuria , but 24 h urinary Ca excretion should be evaluated in healthy persons receiving vitamin D3 supplementation in weekly single doses of 1250 μg ( 50 000 IU ) CONTEXT Public health authorities around the world recommend widely variable supplementation strategies for adults , whereas several professional organizations , including The Endocrine Society , recommend higher supplementation . METHODS We analyzed published r and omized controlled clinical trials to define the optimal intake or vitamin D status for bone and extraskeletal health . CONCLUSIONS The extraskeletal effects of vitamin D are plausible as based on pre clinical data and observational studies . However , apart from the beneficial effects of 800 IU/d of vitamin D3 for reduction of falls in the elderly , causality remains yet unproven in r and omized controlled trials ( RCTs ) . The greatest risk for cancer , infections , cardiovascular and metabolic diseases is associated with 25-hydroxyvitamin D ( 25OHD ) levels below 20 ng/mL. There is ample evidence from RCTs that calcium and bone homeostasis , estimated from serum 1,25-dihydroxyvitamin D and PTH , calcium absorption , or bone mass , can be normalized by 25OHD levels above 20 ng/mL. Moreover , vitamin D supplementation ( 800 IU/d ) in combination with calcium can reduce fracture incidence by about 20 % . Such a dose will bring serum levels of 25OHD above 20 ng/mL in nearly all postmenopausal women . Based on calculations of the metabolic clearance of 25OHD , a daily intake of 500 - 700 IU of vitamin D3 is sufficient to maintain serum 25OHD levels of 20 ng/mL. Therefore , the recommendations for a daily intake of 1500 - 2000 IU/d or serum 25OHD levels of 30 ng or higher for all adults or elderly subjects , as suggested by The Endocrine Society Task Force , are premature . Fortunately , ongoing RCTs will help to guide us to solve this important public health question BACKGROUND It is unclear whether and at what dose vitamin D supplementation affects insulin resistance ( IR ) . OBJECTIVE We sought to investigate whether vitamin D at doses higher than currently recommended decreases indexes of IR in an ambulatory population of overweight elderly subjects . DESIGN This double-blind , r and omized , controlled multicenter trial enrolled 257 elderly overweight individuals aged ≥65 y with baseline 25-hydroxyvitamin D [ 25(OH)D ] concentrations between 10 and 30 ng/mL. All subjects received 1000 mg calcium citrate/d , with vitamin D administered weekly at an equivalent dose of 600 or 3750 IU/d . The homeostasis model assessment ( HOMA ) of IR index at 1 y was the primary outcome . We also assessed the McAuley index . RESULTS In total , 222 subjects ( 55 % women ) with a mean ± SD age and body mass index ( BMI ; in kg/m(2 ) ) of 71 ± 4 y and 30 ± 4 , respectively , completed the study . Subjects ' baseline characteristics , including IR indexes , were similar across groups : 69 % had prediabetes , 54 % had hypertension ( 47 % were taking antihypertensive medications ) , and 60 % had hyperlipidemia , nearly half of whom were receiving lipid-lowering drugs . At 1 y , mean ± SD serum 25(OH)D increased from 20 ± 7 to 26 ± 7 ng/mL in the low-dose arm ( P < 0.0001 ) and from 21 ± 8 to 36 ± 10 ng/mL in the high-dose arm ( P < 0.001 ) . Median HOMA-IR indexes did not change compared with baseline concentrations and were similar in the high- [ 2.2 ( IQR : 1.5 , 2.9 ) ] and low-dose [ 2.3 ( IQR : 1.6 , 3.3 ] treatment groups . Adjusted analyses showed that HOMA-IR was predicted by the baseline HOMA index and BMI but not by vitamin D dose , baseline serum 25(OH)D , or change in 25(OH)D.  CONCLUSION Vitamin D3 at 3750 IU/d did not improve HOMA-IR compared with the Institute of Medicine Recommended Dietary Allowance of 600 IU/d in elderly overweight individuals . This trial was registered at clinical trials.gov as NCT01315366 Vitamin D has been shown to be an important immune system regulator . Vitamin D insufficiency during winter may cause increased susceptibility to upper respiratory tract infections ( URIs ) . To determine whether vitamin D supplementation during the winter season prevents or decreases URI symptoms , 162 adults were r and omized to receive 50 microg vitamin D3 ( 2000 IU ) daily or matching placebo for 12 weeks . A bi-weekly question naire was used to record the incidence and severity of URI symptoms . There was no difference in the incidence of URIs between the vitamin D and placebo groups ( 48 URIs vs. 50 URIs , respectively , P=0.57 ) . There was no difference in the duration or severity of URI symptoms between the vitamin D and placebo groups [ 5.4+/-4.8 days vs. 5.3+/-3.1 days , respectively , P=0.86 ( 95 % CI for the difference in duration -1.8 to 2.1 ) ] . The mean 25-hydroxyvitamin D level at baseline was similar in both groups ( 64.3+/-25.4 nmol/l in the vitamin D group ; 63.0+/-25.8 nmol/l in the placebo group ; n.s . ) . After 12 weeks , 25-hydroxyvitamin D levels increased significantly to 88.5+/-23.2 nmol/l in the vitamin D group , whereas there was no change in vitamin D levels in the placebo group . There was no benefit of vitamin D3 supplementation in decreasing the incidence or severity of symptomatic URIs during winter . Further studies are needed to determine the role of vitamin D in infection Objectives : To measure prevalence of vitamin D deficiency in Saudi Arabia , unveil the life style , nutritional habits and status , as well as identify the potential risk factors . Method : A school-based survey targeting Saudi school students and employees was conducted during the period from 2013 to 2014 using multistage cluster r and om sample in Central , Western and Eastern regions . The prevalence of vitamin D deficiency and difference between various population subgroups were calculated . Logistic regression analysis was used to determine the predictors of potential risk factors . Results : Prevalence of vitamin D deficiency was 49.5 % in students and 44 % in employees .  Life style was not adequate to protect against vitamin D depletion . Unhealthy nutritional habits were widespread , some manifested in childhood while others manifested later in life . Living in the Eastern region , females , 16 - 19 years of age , low economic class , obese and lack of omega 3 supplements were risk factors in students . Employees living in the Eastern region , females , middle-income class , carbonated soft drink consumers , and lack of multivitamin supplements were at higher risk . Conclusion : There is a need for a health awareness program using evidence -based recommendations . Screening for early detection and correction of the condition should be proposed to be part of the national health strategy . There is need for identifying the burden of vitamin D deficiency on other diseases to control and improve the prognosis of these conditions Background : Vitamin D supplementation has been proposed as a potential strategy to prevent  type 2 diabetes .  Existing clinical trials have been limited by short duration , low doses of vitamin D , variability in participants ' vitamin D-deficiency status , and the use of surrogate measures of body composition , insulin sensitivity , and insulin secretion . Objective : To address existing knowledge gaps , we conducted a double-blind , r and omized , placebo-controlled trial to investigate whether vitamin D supplementation that is provided in a sufficient dose and duration to vitamin D-deficient individuals would improve insulin sensitivity or secretion as measured with the use of gold-st and ard methods . We hypothesized that vitamin D supplementation would improve insulin sensitivity and secretion compared with placebo . Design : Sixty-five overweight or obese , vitamin D-deficient ( 25-hydroxyvitamin D [ 25(OH)D ] concentration ≤50 nmol/L ) adults were r and omly assigned to receive either a bolus oral dose of 100,000 IU cholecalciferol followed by 4000 IU cholecalciferol/d or a matching placebo for 16 wk . Before and after the intervention , participants received gold-st and ard assessment s of body composition ( via dual X-ray absorptiometry ) , insulin sensitivity ( via hyperinsulinemic-euglycemic clamps ) , and insulin secretion [ via intravenous-glucose-tolerance tests ( IVGTTs ) ] . Results : Fifty-four participants completed the study [ 35 men and 19 women ; mean ± SD age : 31.9 ± 8.5 y ; body mass index ( in kg/m2 ) : 30.9 ± 4.4 ] . 25(OH)D increased with vitamin D supplementation compared with placebo ( 57.0 ± 21.3 compared with 1.9 ± 15.1 nmol/L , respectively ; P = 0.02 ) . Vitamin D and placebo groups did not differ in change in insulin sensitivity ( 0.02 ± 2.0 compared with -0.03 ± 2.8 mg · kg-1 · min-1 , respectively ; P = 0.9 ) or first-phase insulin secretion ( -21 ± 212 compared with 24 ± 184 mU/L , respectively ; P = 0.9 ) . Results remained nonsignificant after adjustment for age , sex , percentage of body fat , sun exposure , physical activity , and dietary vitamin D intake ( P > 0.1 ) . Conclusions : Vitamin D supplementation does not improve insulin sensitivity or secretion in vitamin D-deficient , overweight or obese adults , despite using high-dose vitamin D supplementation and robust endpoint measures . Therefore , it is unlikely that vitamin D supplementation would be an effective strategy for reducing diabetes risk even in vitamin D-deficient population s. This trial was registered at clinical trials.gov as NCT02112721 BACKGROUND Older adults may be more prone to developing vitamin D deficiency than younger adults . Dietary requirements for vitamin D in older adults are based on limited evidence . OBJECTIVE The objective was to establish the dietary intake of vitamin D required to maintain serum 25-hydroxyvitamin D [ 25(OH)D ] concentrations above various cutoffs between 25 and 80 nmol/L during wintertime , which accounted for the effect of summer sunshine exposure and diet . DESIGN A r and omized , placebo-controlled , double-blind , 22-wk intervention was conducted in men and women aged > /=64 y ( n = 225 ) at supplemental levels of 0 , 5 , 10 , and 15 microg vitamin D(3)/d from October 2007 to March 2008 . RESULTS Clear dose-related increments ( P < 0.0001 ) in serum 25(OH)D were observed with increasing supplemental vitamin D(3 ) intakes . The slope of the relation between total vitamin D intake and serum 25(OH)D was 1.97 nmol . L(-1 ) . microg intake(-1 ) . The vitamin D intake that maintained serum 25(OH)D concentrations > 25 nmol/L in 97.5 % of the sample was 8.6 microg/d . Intakes were 7.9 and 11.4 microg/d in those who reported a minimum of 15 min daily summer sunshine exposure or less , respectively . The intakes required to maintain serum 25(OH)D concentrations of > 37.5 , > 50 , and > 80 nmol/L in 97.5 % of the sample were 17.2 , 24.7 , and 38.7 microg/d , respectively . CONCLUSION To ensure that the vitamin D requirement is met by the vast majority ( > 97.5 % ) of adults aged > /=64 y during winter , between 7.9 and 42.8 microg vitamin D/d is required , depending on summer sun exposure and the threshold of adequacy of 25(OH)D. This trial was registered at http://www.controlled-trials.com/IS RCT N20236112 as IS RCT N registration no. IS RCT N20236112 Objective : To evaluate the effect of isolated vitamin D supplementation ( VITD ) on the rate of falls and postural balance in postmenopausal women fallers . Methods : In this double-blind , placebo-controlled trial , 160 Brazilian younger postmenopausal women were r and omized into two groups : VITD group , vitamin D3 supplementation 1,000 IU/day/orally ( n = 80 ) and placebo group ( n = 80 ) . Women with amenorrhea at least 12 months , age 50 to 65 years , and a history of falls ( previous 12 months ) were included . Those with neurological or musculoskeletal disorders , vestibulopathies , drugs use that could affect balance and osteoporosis were excluded . The intervention time was 9 months . Postural balance was assessed by stabilometry ( computerized force platform ) and investigation on the occurrence/recurrence of falls was performed by interviews . The plasma concentration of 25-hydroxyvitamin D [ 25(OH)D ] was measured by high-performance liquid chromatography . Statistical analysis was achieved by intention-to-treat , using analysis of variance , Student 's t test , Tukey test , chi-square , and logistic regression . Results : After 9 months , mean values of 25(OH)D increased from 15.0 ± 7.5 ng/mL to 27.5 ± 10.4 ng/mL ( + 45.4 % ) in the VITD group , and decreased from 16.9 ± 6.7 ng/mL to 13.8 ± 6.0 ng/mL ( −18.5 % ) in the placebo group ( P < 0.001 ) . The occurrence of falls was higher in the placebo group ( + 46.3 % ) with an adjusted risk of 1.95 ( 95 % confidence interval [ CI ] 1.23 - 3.08 ) times more likely to fall and 2.80 ( 95 % CI 1.43 - 5.50 ) times higher for recurrent falls compared to the VITD group ( P < 0.001 ) . There was reduction in body sway by stabilometry , with lower amplitude of antero-posterior ( −35.5 % ) and latero-lateral ( −37.0 % ) oscillation , only in the VITD group ( P < 0.001 ) . Conclusions : In Brazilian postmenopausal women fallers  , isolated vitamin D supplementation for 9 months result ed in a lower incidence of falls and improvement in postural balance BACKGROUND & AIMS The impact of vitamin D supplementation in overweight and obese adults during resistance training on body composition , muscle function , and glucose tolerance was investigated . METHODS Twenty-three overweight and obese ( age : 26.1±4.7 y ; BMI : 31.3±3.2 kg/m(2 ) ; 25-hydroxyvitamin D : 19.3±7.2 ng/mL ) adults were recruited for participation in a double-blind , placebo-controlled trial . Participants were r and omly divided into vitamin D ( VitD , 4000 IU/d ; 5 females , 5 males ) and placebo ( PL ; 7 females , 6 males ) groups . Both groups completed 12 weeks of resistance training . 25-hydroxyvitamin D , parathyroid hormone , body composition , and glucose tolerance were assessed at baseline and 12 weeks . Muscle function ( strength and power ) was assessed at baseline , 4 , 8 , and 12 weeks . RESULTS During the intervention , 25-hydroxyvitamin D increased and parathyroid hormone decreased in the VitD group ( P<0.05 ) . Peak power was significantly increased at 4 weeks in the VitD group only ( P<0.05 ) . Regression analysis revealed an inverse association between the change in 25-hydroxyvitamin D with the change in waist-to-hip ratio ( R(2)=0.205 , P=0.02 ) . No other improvements were observed with supplementation . CONCLUSIONS Vitamin D supplementation in overweight and obese adults during resistance training induced an early improvement in peak power , and elevated vitamin D status was associated with reduced waist-to-hip ratio . CLINICAL TRIAL REGISTRATION NUMBER NCT01199926 BACKGROUND Low serum 25-hydroxyvitamin D [ 25(OH)D ] concentrations have been associated with insulin resistance , the metabolic syndrome , and type 2 diabetes . Because many non-Western immigrants in the Netherl and s are vitamin D deficient , obese , and at high risk of diabetes , vitamin D supplementation may contribute to prevent diabetes and insulin resistance . OBJECTIVE We examined the effect of vitamin D supplementation on insulin sensitivity and β cell function in overweight , vitamin D-deficient , non-Western immigrants at high risk of diabetes . DESIGN The study was a 16-wk , r and omized , placebo-controlled trial . A total of 130 non-Western immigrants with prediabetes ( fasting glucose concentration > 5.5 mmol/L or r and om glucose concentration from 7.8 to 11.1 mmol/L ) and vitamin D deficiency ( serum 25[OH]D concentration < 50 nmol/L ) were r and omly assigned after stratification by sex to receive either cholecalciferol ( 1200 IU/d ) or a placebo for 16 wk . All participants received 500 mg Ca/d as calcium carbonate . The primary outcome was the difference in the area under the curve of insulin and glucose after a 75-g oral-glucose-tolerance test after 4 mo of treatment . Secondary outcomes were insulin-sensitivity variables , β cell-function variables , and metabolic syndrome . RESULTS Mean serum 25(OH)D concentrations increased significantly in the vitamin D compared with placebo groups . After 4 mo of therapy , the mean between-group difference was 38 nmol/L ( 95 % CI : 32.1 , 43.9 nmol/L ; P < 0.001 ) . There was no significant effect on insulin sensitivity and β cell function . In a post hoc analysis , when patients with diabetes at baseline were excluded , a significant increase in the insulinogenic index was observed in participants who obtained a 25(OH)D concentration ≥60 nmol/L ( P = 0.040 ) . CONCLUSIONS Vitamin D supplementation in non-Western vitamin D-deficient immigrants with prediabetes did not improve insulin sensitivity or β cell function or change the incidence of metabolic syndrome . However , after the exclusion of diabetic subjects , an improvement in the insulinogenic index was observed in participants who obtained a 25(OH)D concentration ≥60 nmol/L. This trial was registered at trialregister.nl as NTR1827 Summary Sunlight deprivation results in vitamin D deficiency but serum vitamin D levels can be maintained above 50nmol/L when supplemented with 50,000IU at least every alternate month . Introduction Anta rct ic expeditioners are exposed to prolonged sunlight deprivation result ing in vitamin D deficiency . We hypothesised that monthly dosing of 50,000 IU vitamin D ( ~1,600 IU daily ) will increase serum 25-hydroxyvitamin D ( 25(OH)D ) , suppress parathyroid hormone ( PTH ) and improve bone mineral density ( BMD ) , 50,000 IU alternate months ( ~800 IU daily ) will maintain these measures , while a single 50,000 IU dose pre-departure ( ~1,00 IU daily ) will not be protective . Methods This was a r and omised double-blind study involving 110 healthy adults : 91 males , mean age 41 years ( range 24–65 years ) working in Anta rct ica for up to 12 months , who we administered 50,000 IU vitamin D3 monthly , alternate months or a single dose pre-departure  . Serum 25(OH)D , PTH , osteocalcin , CTx and calcium were assessed at baseline , mid- and end of expedition . Proximal femur and lumbar spine BMD were assessed pre- and post-expedition . Results Baseline 25(OH)D was 59 ± 14 nmol/L. By mid-expedition , 25(OH)D increased by 7 nmol/L in those supplemented monthly ( p < 0.05 ) and remained unchanged in those supplemented in alternate months . In those given a single dose pre-departure , 25(OH)D decreased by 8 nmol/L ( p < 0.05 ) and PTH increased by 27 % ( p < 0.09 ) . Serum osteocalcin increased by ~22 % in all groups but BMD remained unchanged . If serum 25(OH)D was > 50 nmol/L at baseline , 25(OH)D was maintained above this level with all regimens . If 25(OH)D was < 50 nmol/L at baseline , monthly or alternate month regimens were needed to achieve levels > 50 nmol/L , the single pre-departure dose was ineffective . Conclusion During sunlight deprivation of up to 12 months , serum 25(OH)D levels can be maintained above 50 nmol/L when expeditioners are provided with 50,000 I U at least every alternate month BACKGROUND Severe vitamin D deficiency causes osteomalacia , yet trials of vitamin D supplementation in the community have not on average demonstrated benefit to bone mineral density ( BMD ) or fracture risk in adults . OBJECTIVE To determine whether monthly high-dose vitamin D supplementation influences BMD in the general population and in those with low 25-hydroxyvitamin D levels . METHODS Two-year sub study of a trial in older community-resident adults . A total of 452 participants were r and omized to receive monthly doses of vitamin D3 100 000 IU , or placebo . The primary end-point was change in lumbar spine BMD . Exploratory analyses to identify thresholds of baseline 25-hydroxyvitamin D for vitamin D effects on BMD were prespecified . RESULTS Intention-to-treat analyses showed no significant treatment effect in the lumbar spine ( between-groups difference 0.0071 g cm-2 , 95%CI : -0.0012 , 0.0154 ) or total body but BMD loss at both hip sites was significantly attenuated by ~1/2 % over 2 years . There was a significant interaction between baseline 25-hydroxyvitamin D and treatment effect ( P = 0.04 ) . With baseline 25-hydroxyvitamin D ≤ 30 nmol L-1 ( n = 46 ) , there were between-groups BMD changes at the spine and femoral sites of ~2 % , significant in the spine and femoral neck , but there was no effect on total body BMD . When baseline 25-hydroxyvitamin D was > 30 nmol L-1 , differences were ~1/2 % and significant only at the total hip . CONCLUSIONS This sub study finds no clinical ly important benefit to BMD  from untargeted vitamin D supplementation of older , community-dwelling adults . Exploratory analyses suggest meaningful benefit in those with baseline 25-hydroxyvitamin D ≤ 30 nmol L-1 . This represents a significant step towards a trial-based definition of vitamin D deficiency for bone health in older adults IMPORTANCE Experts debate optimal 25-hydroxyvitamin D ( 25[OH]D ) levels for musculoskeletal health . OBJECTIVE To compare the effects of placebo , low-dose cholecalciferol , and high-dose cholecalciferol on 1-year changes in total fractional calcium absorption , bone mineral density , Timed Up and Go and five sit-to-st and tests , and muscle mass in postmenopausal women with vitamin D insufficiency . DESIGN , SETTING , AND PARTICIPANTS This r and omized , double-blind , placebo-controlled clinical trial was conducted at a single center in Madison , Wisconsin , from May 1 , 2010 , through July 31 , 2013 , and the final visit was completed on August 8 , 2014 . A total of 230 postmenopausal women 75 years or younger with baseline 25(OH)D levels of 14 through 27 ng/mL and no osteoporosis were studied . INTERVENTIONS Three arms included daily white and twice monthly yellow placebo ( n=76 ) , daily 800 IU vitamin D3 and twice monthly yellow placebo ( n=75 ) , and daily white placebo and twice monthly 50,000 IU vitamin D3 ( n=79 ) . The high-dose vitamin D regimen achieved and maintained 25(OH)D levels≥30 ng/mL. MAIN OUTCOMES AND MEASURES Outcome measures were 1-year change in total fractional calcium absorption using 2 stable isotopes , bone mineral density and muscle mass using dual energy x-ray absorptiometry , Timed Up and Go and five sit-to-st and tests , functional status ( Health Assessment Question naire ) , and physical activity ( Physical Activity Scale for the Elderly ) , with Benjamini-Hochberg correction of P values to control for the false discovery rate . RESULTS After baseline absorption was controlled for , calcium absorption increased 1 % ( 10 mg/d ) in the high-dose arm but decreased 2 % in the low-dose arm ( P = .005 vs high-dose arm ) and 1.3 % in the placebo arm ( P = .03 vs high-dose arm ) . We found no between-arm changes in spine , mean total-hip , mean femoral neck , or total-body bone mineral density , trabecular bone score , muscle mass , and Timed Up and Go or five sit-to-st and test scores . Likewise , we found no between-arm differences for numbers of falls , number of fallers , physical activity , or functional status . CONCLUSIONS AND RELEVANCE High-dose cholecalciferol therapy increased calcium absorption , but the effect was small and did not translate into beneficial effects on bone mineral density , muscle function , muscle mass , or falls . We found no data to support experts ' recommendations to maintain serum 25(OH)D levels of 30 ng/mL or higher in postmenopausal women . Instead , we found that low- and high-dose cholecalciferol were equivalent to placebo in their effects on bone and muscle outcomes in this cohort of postmenopausal women with 25(OH)D levels less than 30 ng/mL. TRIAL REGISTRATION clinical trials.gov Identifier : NCT00933244 The link between African-Americans ’ disproportionate rates of diabetes , obesity and vitamin D deficiency may be marked by C-peptide as an indicator of insulin secretion . We hypothesize that vitamin D supplementation will increase C-peptide , a marker of insulin secretion . During 3 winters from 2007 - 2010 , 328 healthy African-Americans ( median age , 51 years ) living in Boston , MA were r and omized into a 4-arm , double-blind trial for 3 months of placebo , 1000 , 2000 , or 4000 IU of vitamin D3 . The differences in non-fasting C-peptide between baseline and 3 months were −0.44 ng/mL for those receiving placebo , −0.10 ng/mL for those receiving 1000 IU/d , 0 ng/mL for those receiving 2000 IU/d , 1.24 ng/mL for those receiving 4000 IU/d ( C-peptide increased 0.42 ng/mL for each additional 1000 IU/d of vitamin D3 , p < 0.001 ) . Vitamin D supplementation  increased C-peptide in overweight African-Americans and may be compatible with other recommendations for diabetes prevention and management including weight loss and increased physical activity BACKGROUND Adolescents are a population group at high risk of low vitamin D status , yet the evidence base for establishing dietary vitamin D requirements remains weak . OBJECTIVE The aim was to establish the distribution of  vitamin D intakes required to maintain serum 25-hydroxyvitamin D [ 25(OH)D ] concentrations above proposed cutoffs ( 25 , 30 , 40 , and 50 nmol/L ) during winter in white males and females ( 14 - 18 y of age ) in the United Kingdom ( 51 ° N ) . DESIGN In a dose-response trial , 110 adolescents ( aged 15.9 ± 1.4 y ; 43 % males ) were r and omly assigned to receive 0 , 10 , or 20 μg vitamin D3 supplements/d for 20 wk during winter . A nonlinear regression model was fit to total vitamin D intake and postintervention serum 25(OH)D concentrations , and regression-predicted values estimated the vitamin D intakes required to maintain serum 25(OH)D concentrations above specific cutoffs . RESULTS Mean ± SD serum 25(OH)D concentrations increased from 49.2 ± 12.0 to 56.6 ± 12.4 nmol/L and from 51.7 ± 13.4 to 63.9 ± 10.6 nmol/L in the 10- and 20-μg/d groups , respectively , and decreased in the placebo group from 46.8 ± 11.4 to 30.7 ± 8.6 nmol/L ( all P ≤ 0.001 ) . Vitamin D intakes required to maintain 25(OH)D concentrations > 25 and > 30 nmol/L in 97.5 % of adolescents were estimated to be 10.1 and 13.1 μg/d , respectively , and 6.6 μg/d to maintain 50 % of adolescents at concentrations > 40 nmol/L. Because the response of 25(OH)D reached a plateau at 46 nmol/L , there is uncertainty in estimating the vitamin D intake required to maintain 25(OH)D concentrations > 50 nmol/L in 97.5 % of adolescents , but it exceeded 30 μg/d . CONCLUSION Vitamin D intakes between 10 and ∼30 μg/d are required by white adolescents during winter to maintain serum 25(OH)D concentrations > 25 - 50 nmol/L , depending on the serum 25(OH)D threshold chosen . This trial was registered at clinical trials.gov as NCT02150122 and as International St and ard R and omized Controlled Trial Number IS RCT N40736890 OBJECTIVES To determine the prevalence of hypovitaminosis D ( serum 25-hydroxyvitamin D<32 ng/mL ; HVD ) in a population of elderly veterans and conduct a preliminary assessment of the efficacy of supplementation with cholecalciferol in correcting HVD . DESIGN R and omized , double-blind , placebo-controlled clinical trial . SETTING Geriatric clinic at the Bruce W. Carter Veterans Affairs Medical Center , Miami , Florida . PARTICIPANTS Veterans aged 70 and older . INTERVENTION Oral cholecalciferol 2,000 IU daily or placebo for 6 months . MEASUREMENTS Serum calcium , 25-hydroxyvitamin D , parathyroid hormone , and 24-hour urinary calcium . RESULTS Of the 34 participants who completed the study , 62 % had HVD at baseline . In the treatment group , mean serum 25-hydroxyvitamin D level rose from 28.4±7.9 ng/mL at baseline to 42.7±10.5 ng/mL at the end of the trial , but levels remained less than 32 ng/mL in three of 17 ( 18 % ) of the participants . In the placebo group , the baseline level of 27.7±8.3 ng/mL remained unchanged ( 28.8±8.7 ng/mL ) . Supplementation did not alter serum or urinary calcium levels and did not result in any adverse events . CONCLUSION These initial observations suggest that , in older veterans  , cholecalciferol 2,000 IU daily for 6 months is generally safe and corrects HVD in most but not all individuals Purpose The Nutrition Societies in Germany , Austria , and Switzerl and recommend a daily intake of 20 µg vitamin D3 for adults when endogenous synthesis is absent . The current study aim ed to eluci date whether this vitamin D3 dose impacts cardiovascular risk markers of adults during the winter months . Methods The study was conducted in Halle ( Saale ) , Germany ( 51o northern latitude ) as a placebo-controlled , double-blinded , r and omised trial ( from January to April ) . A total of 105 apparently healthy subjects ( male and female , 20–71 years old ) were included . Subjects were r and omly allocated to two groups . One group received a daily 20-µg vitamin D3 dose ( n = 54 ) , and the other group received a placebo ( n = 51 ) for 12 weeks . Outcome measures included blood pressure , heart rate , concentrations of renin , aldosterone , serum lipids and vascular calcification markers , and haematologic variables such as pro-inflammatory monocytes . Results Blood pressure and systemic cardiovascular risk markers remained unchanged by vitamin D3 supplementation , although serum 25-hydroxyvitamin D3 increased from 38 ± 14 to 73 ± 16 nmol/L at week 12 . The placebo and vitamin D groups did not differ in their final cardiovascular risk profile . Conclusion Daily supplementation of 20 µg vitamin D3 during winter is unlikely to change cardiovascular risk profile Severe vitamin D deficiency in mothers and their breastfed infants is a significant health problem in the Middle East . Supplementation of the breastfed infant alone with the recommended dose of vitamin D may be insufficient in high-risk population . We investigated the effect of combined maternal and infant vitamin D supplementation on vitamin D status of the breastfed infant . We examined also the effect of supplementation on vitamin D antirachitic activity of breast milk in a subset of mothers . Healthy breastfeeding mothers ( n = 90 ) were r and omly assigned to 2000 IU daily ( group 1 ) or 60,000 IU monthly ( group 2 ) of vitamin D(2 ) , and all their infants ( n = 92 ) received 400 IU daily of vitamin D(2 ) for 3 months . Most infants had vitamin D deficiency - 25-hydroxyvitamin D [ 25(OH)D ] < or= 37.5 nmol L(-1)- at study entry .  Serum 25(OH)D concentrations at 3 months increased significantly from baseline in infants of mothers in group 1 ( 13.9 + /- 8.6 vs. 49.6 + /- 18.5 nmol L(-1 ) , P < 0.0001 ) and group 2 ( 13.7 + /- 12.1 vs. 44.6 + /- 15.0 nmol L(-1 ) , P < 0.0001 ) . Maternal and infant serum 25(OH)D concentrations correlated positively at baseline ( r = 0.36 , P = 0.01 ) and 3 months ( r = 0.46 , P = 0.002 ) . Milk antirachitic activity increased from undetectable ( < 20 IU L(-1 ) ) to a median of 50.9 IU L(-1 ) . In conclusion , combined maternal and infant vitamin D supplementation was associated with a threefold increase in infants ' serum 25(OH)D concentrations and a 64 % reduction in the prevalence of vitamin D deficiency without causing hypervitaminosis CONTEXT Two reports suggested that vitamin D2 is less effective than vitamin D3 in maintaining vitamin D status . OBJECTIVE Our objective was to determine whether vitamin D2 was less effective than vitamin D3 in maintaining serum 25-hydroxyvitamin D levels or increased the catabolism of 25-hydroxyvitamin D3 . SUBJECTS AND DESIGN This was a r and omized , placebo-controlled , double-blinded study of healthy adults ages 18 - 84 yr who received placebo , 1000 IU vitamin D3 , 1000 IU vitamin D2 , or 500 IU vitamin D2 plus 500 IU vitamin D3 daily for 11 wk at the end of the winter . RESULTS Sixty percent of the healthy adults were vitamin D deficient at the start of the study . The circulating levels of 25-hydroxyvitamin D ( mean+/-sd ) increased to the same extent in the groups that received 1000 IU daily as vitamin D2 ( baseline 16.9+/-10.5 ng/ml ; 11 wk 26.8+/-9.6 ng/ml ) , vitamin D3 ( baseline 19.6+/-11.1 ng/ml ; 11 wk 28.9+/-11.0 ng/ml ) , or a combination of 500 IU vitamin D2 and 500 IU vitamin D3 ( baseline 20.2+/-10.4 ng/ml ; 11 wk 28.4+/-7.7 ng/ml ) . The 25-hydroxyvitamin D3 levels did not change in the group that received 1000 IU vitamin D2 daily . The 1000 IU dose of vitamin D2 or vitamin D3 did not raise 25-hydroxyvitamin D levels in vitamin D-deficient subjects above 30 ng/ml . CONCLUSION A 1000 IU dose of vitamin D2 daily was as effective as 1000 IU vitamin D3 in maintaining serum 25-hydroxyvitamin D levels and did not negatively influence serum 25-hydroxyvitamin D3 levels . Therefore , vitamin D2 is equally as effective as vitamin D3 in maintaining 25-hydroxyvitamin D status Vitamin D deficiency leads to secondary hyperparathyroidism , increased bone turnover , and bone loss and , when severe , to osteomalacia . Vitamin D deficiency is common in elderly people , especially the institutionalized . The definition of vitamin D deficiency is hampered by the fact that large interlaboratory differences exist in assays for serum 25-hydroxyvitamin D ( 25OHD ) , the main circulating metabolite . The international Multiple Outcomes of Raloxifene Evaluation study , a large prospect i ve intervention trial in postmenopausal women with osteoporosis , offered the opportunity to compare vitamin D status and parathyroid function throughout many countries over the world . For this study , baseline data were available from 7564 postmenopausal women from 25 countries on 5 continents . All women had osteoporosis , i.e. bone mineral density ( BMD ) at femoral neck or lumbar spine was lower than t-score -2.5 , or they had 2 vertebral fractures .  Serum 25OHD was measured by RIA , and  serum PTH  was measured by immunoradiometric assay .  BMD was measured by dual x-ray absorptiometry . The mean ( + /-SD ) serum 25OHD was 70.8 + /- 30.9 nmol/L. A low serum 25OHD ( < 25 nmol/L ) was observed in 4.1 % of all women in the Multiple Outcomes of Raloxifene Evaluation study , ranging from 0 % in south east Asia ( very few patients ) to 8.3 % in southern Europe . Serum 25OHD was between 25 - 50 nmol/L in 24.3 % of the women . Serum 25OHD showed a significant seasonal relationship , with lower values in all regions in winter . Serum PTH correlated negatively with serum 25OHD ( r = -0.25 ; P < 0.001 ) . This significant negative correlation was observed in all regions . When serum 25OHD was less than 25 , 25 - 50 , or more than 50 nmol/L , respectively , mean serum PTH levels were 4.8 , 4.1 , and 3.5 pmol/L , respectively ( by ANOVA , P < 0.001 ) . Similarly , mean alkaline phosphatase levels were 83.7 , 79.1 , and 75.7 U/L ( P < 0.001 ) , respectively , with increasing serum 25OHD . The effect of serum 25OHD on BMD was only significant for the BMD of the trochanter where a serum 25OHD level less than 25 nmol/L was associated with a 4 % lower BMD . After 6 months of treatment with vitamin D(3 ) ( 400 - 600 IU/day ) and calcium ( 500 mg/day ) , serum 25OHD increased from 70.8 + /- 29.8 to 92.3 + /- 28.6 nmol/L. Serum PTH decreased significantly after 6 months of treatment , and this decrease depended on baseline serum 25OHD . When baseline serum 25OHD was less than 25 , 25 - 50 , or more than 50 nmol/L , respectively , serum PTH decreased by 0.8 , 0.5 , or 0.2 pmol/L , respectively ( P < 0.001 ) . In conclusion , serum 25OHD was less than 25 nmol/L in 4 % of the women , and this was associated with a 30 % higher serum PTH . In 24 % of the women  serum 25OHD was between 25 - 50 nmol/L , associated with a 15 % higher level of serum PTH compared with women with a serum 25OHD greater than 50 nmol/L. A low serum 25OHD level was also associated with higher serum alkaline phosphatase and lower BMD of the trochanter . Treatment with vitamin D(3 ) and calcium increased serum 25OHD and decreased serum PTH significantly ; the effect was greater for lower baseline serum 25OHD OBJECTIVES Engagement in high volumes of physical activity coupled with energy restriction during periods of musculoskeletal development may compromise bone health . Jockeys limit caloric intakes on a weekly basis often from their mid-to-late teens . The aim of this study was to establish whether calcium and vitamin D supplementation would improve bone turnover markers ( BTM ) and non-weight bearing bone properties of young male jockeys . DESIGN A six-month r and omised , double-blinded , placebo-controlled trial with two groups of apprentice male jockeys was conducted . METHODS Participants ( age 20.18±3.23years ) were supplemented with 800 mg of calcium and 400IU of vitamin D ( n=8 ) or a placebo ( n=9 ) daily . Bone properties were assessed at the ultra-distal ( 4 % ) and proximal ( 66 % ) radius using pQCT at baseline and six months . Vitamin D , P1NP and CTX were assessed . RESULTS ANCOVA results for blood-borne markers indicated higher vitamin D levels ( 18.1 % , p=0.014 , partial η2=0.38 ) and lower CTX ( ng·L-1 ) ( -24.8 % , p=0.011 , partial η2=0.40 ) in the supplemented group with no differences observed in P1NP . Analysis of bone variables indicated no between group differences in either trabecular or cortical bone properties at the 4 % and 66 % sites post-intervention . CONCLUSIONS This trial is the first to examine the efficacy of calcium and vitamin D supplementation in improving non-weight bearing bone properties in a young male athletic population . Results indicate positive alterations to bone metabolism ; however , longer duration or higher dosage appears to be required to detect changes in bone material properties at the radius . Further examination of such interventions in weight-restricted athletes is warranted Background Insufficiency of 25‐hydroxyvitamin D [ 25(OH)D ] has been associated with dementia and cognitive decline . However , the effects of vitamin D supplementation on cognition are unclear . It was hypothesized that high dose vitamin D3 supplementation would result in enhanced cognitive functioning , particularly among adults whose 25(OH)D levels were insufficient ( < 75 nmol/L ) at baseline . Methods Healthy adults ( n = 82 ) from northern British Columbia , Canada ( 54 ° north latitude ) with baseline 25(OH)D levels ≤100 nmol/L were r and omized and blinded to High Dose ( 4000 IU/d ) versus Low Dose ( 400 IU/d ) vitamin D3 ( cholecalciferol ) for 18 weeks . Baseline and follow‐up serum 25(OH)D and cognitive performance were assessed and the latter consisted of : Symbol Digit Modalities Test , verbal ( phonemic ) fluency , digit span , and the CANTAB ® computerized battery . Results : There were no significant baseline differences between Low ( n = 40 ) and High ( n = 42 ) dose groups . Serum 25(OH)D increased significantly more in the High Dose ( from 67.2 ± 20 to 130.6 ± 26 nmol/L ) than the Low Dose group ( 60.5 ± 22 to 85.9 ± 16 nmol/L ) , p = 0.0001 . Performance improved in the High Dose group on nonverbal ( visual ) memory , as assessed by the Pattern Recognition Memory task ( PRM ) , from 84.1 ± 14.9 to 88.3 ± 13.2 , p = 0.043 ( d = 0.3 ) and Paired Associates Learning Task , ( PAL ) number of stages completed , from 4.86 ± 0.35 to 4.95 ± 0.22 , p = 0.044 ( d = 0.5 ) , but not in the Low Dose Group . Mixed effects modeling controlling for age , education , sex and baseline performance revealed that the degree of improvement was comparatively greater in the High Dose Group for these tasks , approaching significance : PRM , p = 0.11 ( d = 0.4 ) , PAL , p = 0.058 ( d = 0.4 ) . Among those who had insufficient 25(OH)D ( < 75 nmol/L ) at baseline , the High Dose group ( n = 23 ) improved significantly ( p = 0.005 , d = 0.7 ) and to a comparatively greater degree on the PRM ( p = 0.025 , d = 0.6 ) . Conclusions Nonverbal ( visual ) memory seems to benefit from higher doses of vitamin D supplementation , particularly among those who are insufficient ( < 75 nmol/L ) at baseline , while verbal memory and other cognitive domains do not . These findings are consistent with recent cross‐sectional and longitudinal studies , which have demonstrated significant positive associations between 25(OH)D levels and nonverbal , but not verbal , memory . While our findings require confirmation , they suggest that higher 25(OH)D is particularly important for higher level cognitive functioning , specifically nonverbal ( visual ) memory , which also utilizes executive functioning processes . HighlightsNovel trial of high versus low dose vitamin D3 on multiple cognitive domainsHigh  dose vitamin D ( 4000 IU/d ) improved nonverbal ( visual ) memory after 18 weeks.25(OH)D levels < 75 nmol/L at baseline may confer more benefit with supplementation Background : Vitamin D insufficiency poses a problem in many parts of the world , the elderly being an especially vulnerable group . This insufficiency results from an inadequate amount of sunshine and a low dietary intake of vitamin D. Typically , insufficiency is accompanied with high intact parathyroid hormone , ( S-iPTH ) concentrations . Aims of the Study : We studied how serum 25-hydroxy vitamin D ( S-25-OHD ) concentrations respond to different doses of vitamin D3 supplementation . Secondly to determine the smallest efficient dose to maintain serum 25-OHD concentration above the insufficiency level . We also studied which dose would be efficient in decreasing S-iPTH concentration in these subjects . Subjects and Methods : Forty-nine 65- to 85-year-old women participated . The women were r and omly assigned into one of four groups receiving 0 ( placebo ) , 5 , 10 or 20 μg of vitamin D3 daily for 12 weeks . Fasting morning blood was drawn at the beginning of the study , and thereafter every second week . Calciotropic variables were assessed from serum and urine sample s. Results : The S-25-OHD concentration increased significantly ( p < 0.001 ) in all supplemented groups [ 5 μg : by 10.9 ( 8.5 ) nmol/L , 10 μg : by 14.4 ( 6.9 ) nmol/L , 20 μg : by 23.7 ( 11.9 ) nmol/L ] , whereas it decreased in the placebo group by 8.3 ( 13.2 ) nmol/L. Equilibrium in S-25-OHD concentration was reached in all groups after 6 weeks of supplementation at 57.7 ( 8.9 ) nmol/L , 59.9 ( 8.9 ) nmol/L and 70.9 ( 8.9 ) nmol/L in the groups with increasing vitamin D supplementation . The dose-response to supplementation decreased with increasing vitamin D status at baseline , r = −0.513 , p = 0.002 . S-iPTH tended to decrease in those with highest dose response to supplementation . Conclusions : A clear dose response was noted in S-25-OHD to different doses of vitamin D3 . The recommended dietary intake of 15 μg is adequate to maintain the S-25-OHD concentration around 40–55 nmol/L during winter , but if the optimal S-25-OHD is higher than that even higher vitamin D intakes are needed . Interestingly , subjects with lower vitamin D status at baseline responded more efficiently to supplementation than those with more adequate status Few year-long vitamin D supplementation trials exist that match seasonal changes . The aim of this study was to determine whether daily oral vitamin D3 at 400 IU or 1000 IU compared with placebo affects annual bone mineral density ( BMD ) change in postmenopausal women in a 1-year double-blind placebo controlled trial in Scotl and . White women aged 60 to 70 years ( n = 305 ) were r and omized to one of two doses of vitamin D or placebo . All participants started simultaneously in January/February 2009 , attending visits at bimonthly intervals with 265 ( 87 % ) women attending the final visit and an additional visit 1 month after treatment cessation . BMD ( Lunar iDXA ) and 1,25-dihydroxyvitamin D[1,25(OH)2 D ] , N-terminal propeptide of type 1 collagen [ P1NP ] , C-terminal telopeptide of type I collagen [ CTX ] , and fibroblast growth factor-23 [ FGF23 ] were measured by immunoassay at the start and end of treatment . Circulating PTH , serum Ca , and total 25-hydroxyvitamin D [ 25(OH)D ] ( latter by t and em mass spectrometry ) were measured at each visit . Mean BMD loss at the hip was significantly less for the 1000 IU vitamin D group ( 0.05 % ± 1.46 % ) compared with the 400 IU vitamin D or placebo groups ( 0.57 % ± 1.33 % and 0.60 % ± 1.67 % , respectively ) ( p < 0.05 ) . Mean ( ± SD ) baseline 25(OH)D was 33.8 ± 14.6 nmol/L ; comparative 25(OH)D change for the placebo , 400 IU , and 1000 IU vitamin D groups was -4.1 ± 11.5 nmol/L , + 31.6 ± 19.8 nmol/L , and + 42.6 ± 18.9 nmol/L , respectively . Treatment did not change markers of bone metabolism , except for a small reduction in PTH and an increase in serum calcium ( latter with 1000 IU dose only ) . The discordance between the incremental increase in 25(OH)D between the 400 IU and 1000 IU vitamin D and effect on BMD suggests that 25(OH)D may not accurately reflect clinical outcome , nor how much vitamin D is being stored Lower urinary tract symptoms ( LUTS ) are common in postmenopausal women , and have been reported inversely associated with vitamin D intake and serum 25-hydroxyvitamin D ( 25(OH)D ) levels . The aim of this study was to investigate if high dose vitamin D supplementation would affect LUTS in comparison to st and ard dose . In a r and omized controlled study including 297 postmenopausal women with low bone mineral density , the participants were allocated to receive capsules of 20 000IU of vitamin D3 twice a week ( high dose group ) or similar looking placebo ( st and ard dose group ) . In addition , all the participants received 1 g of calcium and 800IU of vitamin D daily . A vali date d question naire regarding LUTS was filled in at baseline and after 12 months . At baseline , 76 women in the high dose group and 82 in the st and ard dose group reported any LUTS . Levels of serum 25(OH)D increased significantly more in the high dose group ( from 64.7 to 164.1nmol/l compared to from 64.1 to 81.8nmol/l , p<0.01 ) . No differences between the groups were seen regarding change in LUTS except for a statistically significant reduction in the reported severity of urine incontinence in the high dose group as compared to the st and ard dose group after one year ( p<0.05 ) . The results need confirmation in a study specifically design ed for this purpose Purpose The effect of 40 μg ( 1,600 IU ) per day of vitamin D3 on serum 25-hydroxyvitamin D ( 25(OH)D ) and markers of bone and mineral metabolism was evaluated . Methods This intervention study was design ed as a double-blind r and omised controlled trial . Forty-five community-dwelling subjects ( 32 females ) , age 55–84 years , at 58 ° North latitude were supplemented for 1 year with 40 μg vitamin D3 plus 1,000 mg calcium per day , or with 1,000 mg calcium per day for controls  . Safety parameters and 25(OH)D , intact parathyroid hormone ( PTH ) , ionized calcium , bone-specific alkaline phosphatase ( BALP ) , and tartrate-resistant acid phosphatase isoform 5b ( TRACP5b ) were measured over the study period . Results All subjects supplemented with vitamin D3 reached a 25(OH)D level above 50 nmol/L. Mean ( SD ) serum 25(OH)D increased from 50.4 ( 13.5 ) nmol/L to 84.2 ( 17.5 ) nmol/L , range 55.0–125.0 nmol/L in the vitamin D3 supplemented group and the corresponding levels for the control group were 47.3 ( 14.1 ) nmol/L and 45.7 ( 13.4 ) nmol/L , range 26.0–73.0 nmol/L. No serious adverse event was recorded and the highest 25(OH)D level reached , 125.0 nmol/L , is well below toxic levels . BALP and TRACP5b did not change significantly over the study period . Conclusions This trial suggests that a daily supplementation with 40 μg vitamin D3 is sufficient to secure a 25(OH)D level of 50 nmol/L. No side effects were observed in the study group OBJECTIVE The purpose of this study was to determine 1,25-dihydroxyvitamin D3 [ 1,25(OH)2D3 ] and 1,25-dihydroxyvitamin D2 [ 1,25(OH)2D2 ] levels in healthy adults consuming 1000 IU vitamin D2 or vitamin D3 per day for 11 weeks . SUBJECTS AND DESIGN Blood from 34 healthy male and female adults , aged 18 to 79 years , from a placebo-controlled , double-blind study who received a placebo , 1000 IU vitamin D3 , or 1000 IU vitamin D2 daily for 11 weeks at end of winter was analyzed . Serum levels of 25-hydroxyvitamin D2 , 25-hydroxyvitamin D3 , 1,25(OH)2D2 , and 1,25(OH)2D3  were determined by liquid chromatography-t and em mass spectroscopy . RESULTS Of the adults , 82 % were vitamin D insufficient ( serum 25-hydroxyvitamin D [ 25(OH)D < 30 ng/mL ] ) at the start of the study . Administration of vitamin D2 and vitamin D3 induced similar increases in total 25(OH)D as well as in 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3 , respectively . Compared with placebo and adjusting for baseline levels , 1000 IU daily of vitamin D2 was associated with a mean increase of 7.4 pg/mL ( 95 % confidence interval , 4.4 - 10.3 ) in 1,25(OH)2D2 , which was accompanied by a mean decrease of 9.9 pg/mL ( -15.8 to -4.0 ) in 1,25(OH)2D3 . No such differences accompanied administration of 1000 IU daily of vitamin D3 . CONCLUSION Vitamin D2 and vitamin D3 were effective in raising and maintaining total serum concentrations of 25(OH)D. Ingestion of vitamin D2 also result ed in an increase in serum concentrations of 1,25(OH)2D2 . This increase was accompanied by a comparable decrease in serum concentrations of 1,25(OH)2D3 ; therefore , the total 1,25-dihydroxyvitamin D [ 1,25(OH)2D ] concentrations did not significantly change after 11 weeks compared with baseline levels . Ingestion of vitamin D3 did not alter serum concentrations of 1,25(OH)2D3 or total 1,25(OH)2D . Therefore , ingestion of 1000 IU vitamin D2 or vitamin D3 for 11 weeks was effective in raising total serum concentrations of 25(OH)D as well as sustaining serum concentrations of total 1,25(OH)2D The comparative efficacy and safety profiles of selected daily 1000 IU , weekly 7000 IU and monthly 30,000 IU vitamin D3—not previously investigated — will be evaluated . Here , a prospect i ve , r and omized clinical trial , comparing efficacy and safety of a daily single dose of 1000 IU ( group A ) to a once-weekly 7000 IU dose ( group B ) , or monthly 30,000 IU dose ( group C ) of vitamin D3 . The present study is a controlled , r and omized , open-label , multicenter clinical trial , 3 months in duration . Sixty-four adult subjects with vitamin D deficiency ( 25OHD<20 ng/ml ) , were included according to the inclusion and exclusion criteria . Dose-responses for increases in serum vitamin 25OHD were statistically equivalent for each of the three groups : A , B and C. Outcomes were 13.0 ± 1.5 ; 12.6 ± 1.1 and 12.9 ± 0.9 ng/ml increases in serum 25OHD per 1000 IU , daily , weekly and monthly , respectively . The treatment of subjects with selected doses restored 25OHD values to levels above 20 ng/ml in all groups . Treatment with distinct administration frequency of vitamin D3 did not exhibit any differences in safety parameters . The daily , weekly and monthly administrations of daily equivalent of 1000 IU of vitamin D3 provide equal efficacy and safety profiles Background : There are conflicting views in the literature as to whether vitamin D2 and vitamin D3 are equally effective in increasing and maintaining serum concentrations of 25-hydroxyvitamin D [ 25(OH)D ] , particularly at lower doses of vitamin D. Objective : We aim ed to investigate whether vitamin D2 or vitamin D3 fortified in juice or food , at a relatively low dose of 15 μg/d , was effective in increasing serum total 25(OH)D and to compare their respective efficacy in South Asian and white European women over the winter months within the setting of a large r and omized controlled trial . Design : A r and omized , double-blind , placebo-controlled food-fortification trial was conducted in healthy South Asian and white European women aged 20 - 64 y ( n = 335 ; Surrey , United Kingdom ) who consumed placebo , juice supplemented with 15 μg vitamin D2 , biscuit supplemented with 15 μg vitamin D2 , juice supplemented with 15 μg vitamin D3 , or biscuit supplemented with 15 μg vitamin D3 daily for 12 wk  . Serum 25(OH)D was measured by liquid chromatography-t and em mass spectrometry at baseline and at weeks 6 and 12 of the study . Results : Postintervention in the 2 ethnic groups combined , both the vitamin D3 biscuit and the vitamin D3 juice groups showed a significantly greater absolute incremental change ( Δ ) in total 25(OH)D when compared with the vitamin D2 biscuit group [ Δ ( 95 % CI ) : 15.3 nmol/L ( 7.4 , 23.3 nmol/L ) ( P < 0.0003 ) and 16.0 nmol/L ( 8.0 , 23.9 nmol/L ) ( P < 0.0001 ) ] , the vitamin D2 juice group [ Δ ( 95 % CI ) : 16.3 nmol/L ( 8.4 , 24.2 nmol/L ) ( P < 0.0001 ) and 16.9 nmol/L ( 9.0 , 24.8 nmol/L ) ( P < 0.0001 ) ] , and the placebo group [ Δ ( 95 % CI ) : 42.3 nmol/L ( 34.4 , 50.2 nmol/L ) ( P < 0.0001 ) and 42.9 nmol/L ( 35.0 , 50.8 nmol/L ) ( P < 0.0002 ) ] . Conclusions : With the use of a daily dose of vitamin D relevant to public health recommendations ( 15 μg ) and in vehicles relevant to food-fortification strategies , vitamin D3 was more effective than vitamin D2 in increasing serum 25(OH)D in the wintertime . Vitamin D3 may therefore be a preferential form to optimize vitamin D status within the general population . This trial was registered at www.controlled-trials.com as IS RCT N23421591 OBJECTIVE To determine whether treatment of low serum vitamin D in pregnant women improves fetal growth indices . STUDY DESIGN In this open-label r and omized clinical trial , 130 Iranian pregnant women ( 24 - 26 weeks of gestation ) with vitamin D deficiency or insufficiency [ 25(OH)D < 30ng/ml ] were divided at r and om into an intervention group and a control group . The control group received 200 mg calcium plus a multivitamin ( containing vitamin D3 400U ) each day , and the intervention group received 200 mg calcium plus a multivitamin ( containing vitamin D3 400U ) each day , plus vitamin D3 ( 50,000U ) each week for 8 weeks . At delivery , maternal and cord blood 25(OH)D levels , maternal weight gain , neonatal length , neonatal weight and neonatal head circumference were compared between two groups . Serum vitamin D was measured using enzyme-linked immunosorbent assay . A multivariate regression analysis was performed to examine the independent effect of maternal vitamin D level on fetal growth indices . RESULTS Mean ( ±st and ard deviation ) length ( intervention group : 49±1.6 cm ; control group : 48.2±1.7 cm ; p=0.001 ) , head circumference ( intervention group : 35.9±0.7 cm ; control group : 35.3±1.0 cm ; p=0.001 ) and weight ( intervention group : 3429±351.9 g ; control group : 3258.8±328.2 g ; p=0.01 ) were higher in the intervention group compared with the control group . Mean maternal weight gain was higher in the intervention group compared with the control group ( 13.3±2.4 kg vs 11.7±2.7 kg ; p=0.006 ) . Multivariate regression analysis for maternal weight gain , neonatal length , neonatal weight and neonatal head circumference showed an independent correlation with maternal vitamin D level . CONCLUSION Treatment of low serum vitamin D during pregnancy improves fetal growth indices and maternal weight gain BACKGROUND Knowledge gaps have contributed to considerable variation among international dietary recommendations for vitamin D. OBJECTIVE We aim ed to establish the distribution of dietary vitamin D required to maintain serum 25-hydroxyvitamin D [ 25(OH)D ] concentrations above several proposed cutoffs ( ie , 25 , 37.5 , 50 , and 80 nmol/L ) during wintertime after adjustment for the effect of summer sunshine exposure and diet . DESIGN A r and omized , placebo-controlled , double-blind 22-wk intervention study was conducted in men and women aged 20 - 40 y ( n = 238 ) by using different supplemental doses ( 0 , 5 , 10 , and 15 microg/d ) of vitamin D(3 ) throughout the winter .  Serum 25(OH)D concentrations were measured by using enzyme-linked immunoassay at baseline ( October 2006 ) and endpoint ( March 2007 ) . RESULTS There were clear dose-related increments ( P < 0.0001 ) in serum 25(OH)D with increasing supplemental vitamin D(3 ) . The slope of the relation between  vitamin D intake and serum 25(OH)D was 1.96 nmol x L(-1 ) x microg(-1 ) intake . The vitamin D intake that maintained serum 25(OH)D concentrations of > 25 nmol/L in 97.5 % of the sample was 8.7 microg/d . This intake ranged from 7.2 microg/d in those who enjoyed sunshine exposure , 8.8 microg/d in those who sometimes had sun exposure , and 12.3 microg/d in those who avoided sunshine . Vitamin D intakes required to maintain serum 25(OH)D concentrations of > 37.5 , > 50 , and > 80 nmol/L in 97.5 % of the sample were 19.9 , 28.0 , and 41.1 microg/d , respectively . CONCLUSION The range of vitamin D intakes required to ensure maintenance of wintertime vitamin D status [ as defined by incremental cutoffs of serum 25(OH)D ] in the vast majority ( > 97.5 % ) of 20 - 40-y-old adults , considering a variety of sun exposure preferences , is between 7.2 and 41.1 microg/d
target: Overall , intervention groups obtained higher 25(OH)D concentration than controls and there was obvious dose – response effect between intake dose and 25(OH)D concentration .
  Baseline 25(OH)D concentration and age were significant indicators for 25(OH)D concentration .
  Conclusions Regional- and age-specific recommended dosages of VitD supplements for population to achieve optimal 25(OH)D concentrations have been suggested
background: Background / Objectives Optimal doses of vitamin D ( VitD ) supplement in different population s are unclear .
  We aim to evaluate the relationship between VitD supplementation and post-intervention serum 25-hydroxyvitamin D [ 25(OH)D ] concentration , to provide a recommended dosage of VitD for achieving an optimal 25(OH)D concentration for different population s .