title: Comparison of daily, weekly, and monthly vitamin D3 in ethanol dosing protocols for two months in elderly hip fracture patients. Overview of the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers Vitamin D2 dose required to rapidly increase 25OHD levels in osteoporotic women Effect of Calcium and Vitamin D Supplementation on Blood Pressure: The Women's Health Initiative Randomized Trial Effects of vitamin D supplementation on 25-hydroxyvitamin D, high-density lipoprotein cholesterol, and other cardiovascular disease risk markers in subjects with elevated waist circumference Calcium/vitamin D supplementation and coronary artery calcification in the Women's Health Initiative Long-term effects of nutrient intervention on markers of bone remodeling and calciotropic hormones in late-postmenopausal women. Preventing fractures among older people living in institutional care: a pragmatic randomised double blind placebo controlled trial of vitamin D supplementation Calcium plus vitamin D supplementation and the risk of breast cancer. Calcium/Vitamin D Supplementation and Cardiovascular Events Efficacy of different doses and time intervals of oral vitamin D supplementation with or without calcium in elderly nursing home residents Calcium plus vitamin D supplementation and the risk of colorectal cancer. Do vitamin D supplements improve the physical capabilities of elderly hospital patients? Calcium plus vitamin D supplementation and the risk of fractures. Serum ionized calcium, intact PTH and novel markers of bone turnover in bedridden elderly patients. Vitamin D(3) is more potent than vitamin D(2) in humans. A randomized, controlled trial of quadriceps resistance exercise and vitamin D in frail older people: the Frailty Interventions Trial in Elderly Subjects (FITNESS). How Much Vitamin D3 Do the Elderly Need? Estimation of the dietary requirement for vitamin D in healthy adults.
abstract: BACKGROUND Different dosing protocol s have been used for vitamin D supplementation , but there has been a lack of comparative data among them . OBJECTIVE Our objective was to determine whether the same cumulative dose of vitamin D3 produces different effects if it is given daily , weekly , or monthly . DESIGN Women , age 81 + /- 8 yr ( + /- sd , n = 48 ) , who had undergone surgery to repair hip fracture were r and omized to vitamin D3-supplementation protocol s at 1,500 IU daily , or 10,500 IU once weekly , or 45,000 IU once every 28 d. The primary outcome measure was the serum 25-hydroxyvitamin D [ 25(OH)D ] concentration attained . RESULTS Initially , serum 25(OH)D concentrations for daily , weekly , and monthly groups were , respectively , 15.13 + /- 6.9 , 15.7 + /- 10.1 , and 16.2 + /- 10.1 ng/ml . By d 7 , these had increased significantly in all the groups ( P < 0.001 ) . On the first day after the monthly dose , both serum 25(OH)D and serum 1,25-dihydroxyvitamin D had increased significantly ( P < 0.012 each ) , whereas these did not change significantly on the day after daily or weekly doses . After 2 months , serum 25(OH)D with daily , weekly , and monthly dosing were , respectively , 33.2 + /- 8.5 , 29.2 + /- 8.9 , and 37.1 + /- 10.3 ng/ml ; there were no significant differences among these values . CONCLUSIONS Supplementation with vitamin D can be achieved equally well with daily , weekly , or monthly dosing frequencies . Therefore , the choice of dose frequency can be based on whichever approach will optimize an individual 's adherence with long-term vitamin D supplementation The Cohort Consortium Vitamin D Pooling Project of Rarer Cancers ( VDPP ) brought together 10 cohorts to conduct a prospect i ve study of the association between vitamin D status , measured as serum concentrations of 25-hydroxyvitamin D ( 25(OH)D ) , and the development of 7 rarer cancer sites : endometrial , esophageal , gastric , kidney , non-Hodgkin lymphoma , ovarian , and pancreatic cancers . The cohorts come from 3 continents , with participants from a wide range of latitude who are racially diverse . Across each cancer site , there was no evidence of a protective association between higher concentrations of 25-hydroxyvitamin D ( > 75 nmol/L ) and cancer outcome . An increased risk at very high levels ( ≥100 nmol/L ) was noted for pancreatic cancer , confirming previous reports . The articles included in this issue detail the overall design and governance of the project , correlates of vitamin D status , and results from the cancer site-specific investigations . The Vitamin D Pooling Project realizes a major goal of consortium efforts , namely , to rigorously test hypotheses for rarer cancer outcomes that may not be adequately addressed in any one prospect i ve cohort study . The results of this study have application for the planning and conduct of intervention trials , especially in determining potential risks 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 Experimental and epidemiological studies suggest that calcium and vitamin D supplements may lower  blood pressure . We examined the effect of calcium plus vitamin D supplementation on blood pressure and the incidence of hypertension in postmenopausal women . The Women 's Health Initiative Calcium/Vitamin D Trial r and omly assigned 36 282 postmenopausal women to receive 1000 mg of elemental calcium plus 400 IU of vitamin D3 daily or placebo in a double-blind fashion . Change in blood pressure and the incidence of hypertension were ascertained . Over a median follow-up time of 7 years , there was no significant difference in the mean change over time in systolic blood pressure ( 0.22 mm Hg ; 95 % CI : −0.05 to 0.49 mm Hg ) and diastolic blood pressure ( 0.11 mm Hg ; 95 % CI : −0.04 to 0.27 mm Hg ) between the active and placebo treatment groups . This null result was robust in analyses accounting for nonadherence to study pills and in baseline subgroups of interest , including black subjects and women with hypertension or high levels of blood pressure , with low intakes of calcium and vitamin D or low serum levels of vitamin D. In 17 122 nonhypertensive participants at baseline , the hazard ratio for incident hypertension associated with calcium/vitamin D treatment was 1.01 ( 95 % CI : 0.96 to 1.06 . ) In postmenopausal  women , calcium plus vitamin D3 supplementation did not reduce either blood pressure or the risk of developing hypertension over 7 years of follow-up The objective of the present trial was to assess the effects of vitamin D supplementation on serum 25-hydroxyvitamin D [ 25(OH)D ] and high-density lipoprotein cholesterol ( HDL-C ) in subjects with high waist circumference . Subjects were r and omly assigned a daily multivitamin and mineral ( MVM ) supplement or a MVM supplement plus vitamin D 1,200 IU/day ( MVM+D ) for 8 weeks . There was a significant difference in mean change for 25(OH)D between the MVM and MVM+D treatment groups ( − 1.2 ± 2.5 nmol/l vs. 11.7 ± 3.0 nmol/l , respectively ; P = 0.003 ) . Vitamin D 1,200 IU/day did not increase 25(OH)D to a desirable level ( ≥ 75 nmol/l ) in 61 % of participants . There were no significant changes in cardiovascular disease risk markers . Thus , vitamin D supplementation with 1,200 IU/day was insufficient to achieve desirable serum 25(OH)D in most participants and did not affect cardiovascular disease risk markers Objective : Coronary artery calcified plaque is a marker for atheromatous plaque burden and predicts future risk of cardiovascular events . The relationship between calcium plus vitamin D ( calcium/D ) supplementation and coronary artery calcium ( CAC ) has not been previously assessed in a r and omized trial setting . We compared CAC scores after trial completion between women r and omized to calcium/vitamin D supplementation and women r and omized to placebo . Methods : In an ancillary sub study of women r and omized to calcium carbonate ( 1,000 mg of elemental calcium daily ) plus vitamin D3 ( 400 IU daily ) or placebo , nested within the Women 's Health Initiative trial of estrogen among women who underwent hysterectomy , we measured CAC with cardiac CT in 754 women aged 50 to 59 years at r and omization . Imaging for CAC was performed at 28 of 40 centers after a mean of 7 years of treatment , and scans were read central ly . CAC scores were measured by a central reading center with masking to r and omization assignments . Results : Posttrial CAC measurements were similar in women r and omized to calcium/D supplementation and those receiving placebo . The mean CAC score was 91.6 for women receiving calcium/D and 100.5 for women receiving placebo ( rank test P value = 0.74 ) . After adjustment for coronary risk factors , multivariate odds ratios for increasing CAC score cutpoints ( CAC > 0 , ≥10 , and ≥100 ) for calcium/D versus placebo were 0.92 ( 95 % CI , 0.64 - 1.34 ) , 1.29 ( 0.88 - 1.87 ) , and 0.90 ( 0.56 - 1.44 ) , respectively . Corresponding odds ratios among women with a 50 % or higher adherence to study pills and for higher levels of CAC ( > 300 ) were similar . Conclusions : Treatment with moderate doses of calcium plus vitamin D3 did not seem to alter coronary artery calcified plaque burden among postmenopausal women . Whether higher or lower doses would affect this outcome remains uncertain BACKGROUND Adequate intakes of calcium and vitamin D reduce bone loss and fracture risk in the elderly . Other nutrients also affect bone health , and adequate intakes may influence bone turnover and balance . OBJECTIVE We compared the long-term effects on bone turnover markers and calciotropic hormones of a multinutrient supplement , a calcium and vitamin D supplement , and dietary instruction aim ed at increasing calcium intake through foods . DESIGN Ninety-nine healthy postmenopausal women participated in a 3-y , r and omized trial , receiving either 1 ) supplemental calcium ( 1450 mg/d ) and vitamin D [ 10 microg ( 400 IU)/d ] , 2 ) calcium , vitamin D , and other nutrients ( multinutrient supplement ) , or 3 ) dietary instruction ( dietary control group ) . Data are from 83 subjects who completed the trial . RESULTS Increases over baseline in calcium intakes and serum 25-hydroxyvitamin D concentrations were sustained over 3 y in all treatment groups . Circulating parathyroid hormone concentrations were reduced at year 1 in all treatment groups but trended toward baseline thereafter . Bone turnover markers followed a similar pattern , and none of the changes in biochemical concentrations differed significantly between groups . CONCLUSIONS All 3 interventions offer long-term feasibility for increasing calcium intake and serum 25-hydroxyvitamin D concentrations . The dietary addition of micronutrients implicated in skeletal physiology confers no obvious bone-sparing effect in healthy postmenopausal women beyond that of calcium and vitamin D alone . The attenuation over time in suppression of parathyroid hormone and bone turnover might help explain why nutrient intervention tends to have less of a bone-sparing effect than do skeletally active medications such as estrogen or bisphosphonates Introduction Osteoporotic fractures in older people are a major and increasing public health problem . We examined the effect of vitamin D supplementation on fracture rate in people living in sheltered accommodation . Methods In a pragmatic double blind r and omised controlled trial of 3 years duration , we examined 3,440 people ( 2,624 women and 816 men ) living in residential or care home . We used four-monthly oral supplementation using 100,000 IU vitamin D2 ( ergocalciferol ) . As a main outcome measure , we used the incidence of first fracture using an intention to treat analysis . This was a multicentre study in 314 care homes or sheltered accommodation complexes in South Wales , UK . Results The vitamin D and placebo groups had similar baseline characteristics . In intention-to-treat analysis , 205 first fractures occurred in the intervention group during a total of 2,846 person years of follow-up ( 7 fractures per 100 people per year of follow-up ) , with 218 first fractures in the control group over 2,860 person years of follow-up . The hazard ratio of 0.95 ( 95 % confidence interval 0.79–1.15 ) for intervention compared to control was not statistically significant . ConclusionS upplementation with four-monthly 100,000 IU of oral vitamin D2 is not sufficient to affect fracture incidence among older people living in institutional care BACKGROUND Although some observational studies have associated higher calcium intake and especially higher vitamin D intake and 25-hydroxyvitamin D levels with lower breast cancer risk , no r and omized trial has evaluated these relationships . METHODS Postmenopausal women ( N = 36 282 ) who were enrolled in a Women 's Health Initiative clinical trial were r and omly assigned to 1000 mg of elemental calcium with 400 IU of vitamin D(3 ) daily or placebo for a mean of 7.0 years to determine the effects of supplement use on incidence of hip fracture . Mammograms and breast exams were serially conducted . Invasive breast cancer was a secondary outcome . Baseline serum 25-hydroxyvitamin D levels were assessed in a nested case-control study of 1067 case patients and 1067 control subjects . A Cox proportional hazards model was used to estimate the risk of breast cancer associated with r and om assignment to calcium with vitamin D(3 ) . Associations between 25-hydroxyvitamin D serum levels and total vitamin D intake , body mass index ( BMI ) , recreational physical activity , and breast cancer risks were evaluated using logistic regression models . Statistical tests were two-sided . RESULTS Invasive breast cancer incidence was similar in the two groups ( 528 supplement vs 546 placebo ; hazard ratio = 0.96 ; 95 % confidence interval = 0.85 to 1.09 ) . In the nested case-control study , no effect of supplement group assignment on breast cancer risk was seen . Baseline 25-hydroxyvitamin D levels were modestly correlated with total vitamin D intake ( diet and supplements ) ( r = 0.19 , P < .001 ) and were higher among women with lower BMI and higher recreational physical activity ( both P < .001 ) . Baseline 25-hydroxyvitamin D levels were not associated with breast cancer risk in analyses that were adjusted for BMI and physical activity ( P(trend ) = .20 ) . CONCLUSIONS Calcium and vitamin D supplementation did not reduce invasive breast  cancer incidence in postmenopausal women . In addition , 25-hydroxyvitamin D levels were not associated with subsequent breast cancer risk . These findings do not support a relationship between total vitamin D intake and 25-hydroxyvitamin D levels with breast cancer risk Background — Individuals with vascular or valvular calcification are at increased risk for coronary events , but the relationship between calcium consumption and cardiovascular events is uncertain . We evaluated the risk of coronary and cerebrovascular events in the Women ’s Health Initiative r and omized trial of calcium plus vitamin D supplementation . Methods and Results — We r and omized 36 282 postmenopausal women 50 to 79 years of age at 40 clinical sites to calcium carbonate 500 mg with vitamin D 200 IU twice daily or to placebo .  Cardiovascular disease was a prespecified secondary efficacy outcome . During 7 years of follow-up , myocardial infa rct ion or coronary heart disease death was confirmed for 499 women assigned to calcium/vitamin D and 475 women assigned to placebo ( hazard ratio , 1.04 ; 95 % confidence interval , 0.92 to 1.18 ) . Stroke was confirmed among 362 women assigned to calcium/vitamin D and 377 assigned to placebo ( hazard ratio , 0.95 ; 95 % confidence interval , 0.82 to 1.10 ) . In subgroup analyses , women with higher total calcium intake ( diet plus supplements ) at baseline were not at higher risk for coronary events ( P=0.91 for interaction ) or stroke ( P=0.14 for interaction ) if assigned to active calcium/vitamin D. Conclusions — Calcium/vitamin D supplementation neither increased nor decreased coronary or cerebrovascular risk in generally healthy postmenopausal women over a 7-year use period Summary The effect of equivalent oral doses of vitamin D3 600 IU/day , 4200 IU/week and 18,000 IU/month on vitamin D status was compared in a r and omized clinical trial in nursing home residents . A daily dose was more effective than a weekly dose , and a monthly dose was the least effective . Introduction It is assumed that equivalent daily , weekly or monthly doses of vitamin D3 equally influence vitamin D status . This was investigated in a r and omized clinical trial in nursing home residents . Methods The study was performed in ten nursing homes including 338 subjects ( 76 male and 262 female ) , with a mean age of 84 ( ± SD 6.3 years ) . They received oral vitamin D3 either 600 IU/day , or 4200 IU/week , or 18,000 IU/month or placebo . After 4 months , calcium was added during 2 weeks , 320 mg/day or 640 mg/day or placebo . Outcome : serum levels of 25-hydroxyvitamin D ( 25(OH)D ) , parathyroid hormone ( PTH ) and bone turnover markers . Statistical approach : linear multilevel analysis . Results At baseline , mean serum 25(OH)D was 25.0 nmol/L ( SD 10.9 ) , and in 98 % , it was lower than 50 nmol/L. After 4 months , mean serum 25(OH)D levels increased to 62.5 nmol/L ( after daily vitamin D3 69.9 nmol/L , weekly 67.2 nmol/L and monthly 53.1 nmol/L , P < 0.001 between groups ) . Median serum PTH levels decreased by 23 % ( p < 0.001 ) . Bone turnover markers did not decrease . Calcium supplementation had no effect on serum PTH and bone turnover . Conclusion Daily vitamin D was more effective than weekly , and monthly administration was the least effective BACKGROUND Higher intake of calcium and vitamin D has been associated with a reduced risk of colorectal cancer in epidemiologic studies and polyp recurrence in polyp-prevention trials . However , r and omized-trial evidence that calcium with vitamin D supplementation is beneficial in the primary prevention of colorectal cancer is lacking . METHODS We conducted a r and omized , double-blind , placebo-controlled trial involving 36,282 postmenopausal women from 40 Women 's Health Initiative centers : 18,176 women received 500 mg of elemental calcium as calcium carbonate with 200 IU of vitamin D3 [ corrected ] twice daily ( 1000 mg of elemental calcium and 400 IU of vitamin D3 ) and 18,106 received a matching placebo for an average of 7.0 years . The incidence of pathologically confirmed colorectal cancer was the design ated secondary outcome . Baseline levels of serum 25-hydroxyvitamin D were assessed in a nested case-control study . RESULTS The incidence of invasive colorectal cancer did not differ significantly between women assigned to calcium plus vitamin D supplementation and those assigned to placebo ( 168 and 154 cases ; hazard ratio , 1.08 ; 95 percent confidence interval , 0.86 to 1.34 ; P=0.51 ) , and the tumor characteristics were similar in the two groups . The frequency of colorectal-cancer screening and abdominal symptoms was similar in the two groups . There were no significant treatment interactions with baseline characteristics . CONCLUSIONS Daily supplementation of calcium with vitamin D for seven years had no effect on the incidence of colorectal cancer  among postmenopausal women . The long latency associated with the development of colorectal cancer , along with the seven-year duration of the trial , may have contributed to this null finding . Ongoing follow-up will assess the longer-term effect of this intervention . ( Clinical Trials.gov number , NCT00000611 . ) A r and omized double-blind controlled trial of the effect of vitamin D supplementation on the abilities of elderly hospital patients to carry out basic activities of daily life is described . Those patients included in the trial had plasma 25-hydroxyvitamin D concentrations which were low or low normal as judged by the normal range in young adults . After 2 to 9 months on the trial there was no significant difference in the performance of the control and treatment groups BACKGROUND The efficacy of calcium with vitamin D supplementation for preventing hip and other fractures in healthy postmenopausal women remains equivocal . METHODS We recruited 36,282 postmenopausal women , 50 to 79 years of age , who were already enrolled in a Women 's Health Initiative ( WHI ) clinical trial . We r and omly assigned participants to receive 1000 mg of elemental [ corrected ] calcium as calcium carbonate with 400 IU of vitamin D3 daily or placebo .  Fractures were ascertained for an average follow-up period of 7.0 years . Bone density was measured at three WHI centers . RESULTS Hip bone density was 1.06 percent higher in the calcium plus vitamin D group than in the placebo group ( P<0.01 ) . Intention-to-treat analysis indicated that participants receiving calcium plus vitamin D supplementation had a hazard ratio of 0.88 for hip fracture ( 95 percent confidence interval , 0.72 to 1.08 ) , 0.90 for clinical spine fracture ( 0.74 to 1.10 ) , and 0.96 for total fractures ( 0.91 to 1.02 ) . The risk of renal calculi increased with calcium plus vitamin D ( hazard ratio , 1.17 ; 95 percent confidence interval , 1.02 to 1.34 ) . Censoring data from women when they ceased to adhere to the study medication reduced the hazard ratio for hip fracture to 0.71 ( 95 percent confidence interval , 0.52 to 0.97 ) . Effects did not vary significantly according to prer and omization serum vitamin D levels . CONCLUSIONS Among healthy postmenopausal women , calcium with vitamin D supplementation result ed in a small but significant improvement in hip bone density , did not significantly reduce hip fracture , and increased the risk of kidney stones . ( Clinical Trials.gov number , NCT00000611 . ) Chronic immobilization could markedly affect calcium and bone metabolism in elderly people . To investigate this , and to test the theory of ' type II ' osteoporosis in bedridden elderly patients with low vitamin D status , 55 such subjects were examined .  Serum concentrations of ionized calcium ( Ca++ ) , intact parathyrin ( PTH ) and two novel markers of bone collagen formation ( carboxyterminal propeptide of type I procollagen ; PICP ) and resorption ( carboxyterminal crosslinked telopeptide of type I collagen ; ICTP ) were measured . The effects on these parameters after 40 weeks of supplementation with vitamin D ( 1000 IU d-1 ) and /or calcium ( 1 g d-1 ) were subsequently prospect ively evaluated . Despite low ( mean 11.6 nmoll-1 ) serum 25-hydroxyvitamin D levels ( 25-OHD ) , those of 1,25-dihydroxy-vitamin D ( 1,25-(OH)2D ) were mostly normal . Neither correlated with Ca++ or PTH . PTH correlated negatively not only with Ca++ ( r = -0.328 , P < 0.05 ) but also with ICTP ( r = -0.306 , P < 0.05 ) . Mean PICP was normal but ICTP was elevated and tended to correlate positively with Ca++ ( r = 0.268 , P = 0.06 ) . Vitamin D supplementation did not change PICP or ICTP considerably , despite slightly increased 1,25-(OH)2D and slightly decreased PTH . Ca++ values were normal and remained stable . In conclusion , Ca++ and PTH are poor indicators of vitamin D status in chronically immobilized elderly subjects . Furthermore , the results suggest that the increased bone resorption is not due to ' type II ' secondary hyperparathyroidism ; rather the resorption is primarily increased . Correction of vitamin D deficiency does not seem to benefit ageing bones unless adequate mechanical loading is provided BACKGROUND Current unitage for the calciferols suggests that equimolar quantities of vitamins D(2 ) ( D2 ) and D(3 ) ( D3 ) are biologically equivalent . Published studies yield mixed results . OBJECTIVE The aim of the study was to compare the potencies of D2 and D3 . DESIGN The trial used a single-blind , r and omized design in 33 healthy adults .  Calciferols were dosed at 50,000 IU/wk for 12 wk . Principal outcome variables were area under the curve for incremental total 25-hydroxyvitamin D [ 25(OH)D ] and change in calciferol content of sc fat . RESULTS Incremental mean ( sd ) 25(OH)D area under the curve at 12 wk was 1366 ng · d/ml ( 516 ) for the D2-treated group and 2136 ( 606 ) for the D3 ( P < 0.001 ) . Mean ( sd ) steady-state 25(OH)D increments showed similar differences : 24 ng/ml for D2 ( 10.3 ) and 45 ng/ml ( 16.2 ) for D3 ( P < 0.001 ) . Subcutaneous fat content of D2 rose by 50 μg/kg in the D2-treated group , and D3 content rose by 104 μg/kg in the D3-treated group . Total calciferol in fat rose by only 33 ng/kg in the D2-treated , whereas it rose by 104 μg/kg in the D3-treated group . Extrapolating to total body fat D3 , storage amounted to just 17 % of the administered dose . CONCLUSION D3 is approximately 87 % more potent in raising and maintaining serum 25(OH)D concentrations and produces 2- to 3-fold greater storage of vitamin D than does equimolar D2 . For neither was there evidence of sequestration in fat , as had been postulated for doses in this range . Given its greater potency and lower cost , D3 should be the preferred treatment option when correcting vitamin D deficiency OBJECTIVES To determine the effectiveness of vitamin D and home-based quadriceps resistance exercise on reducing falls and improving the physical health of frail older people after hospital discharge . DESIGN Multicenter , r and omized , controlled trial with a factorial design . SETTING Five hospitals in Auckl and , New Zeal and , and Sydney , Australia . PARTICIPANTS Two hundred forty-three frail older people . INTERVENTIONS Patients were r and omized to receive a single dose of vitamin D ( calciferol , 300,000 IU ) or placebo tablets and 10 weeks of high-intensity home-based quadriceps resistance exercise or frequency-matched visits . MEASUREMENTS The primary endpoints were physical health according to the short-form health survey at 3 months and falls over 6 months . Physical performance and self-rated function were secondary endpoints . Assessment s took place in the participants ' homes at 3 and 6 months after r and omization and were performed by blinded assessors . RESULTS There was no effect of either intervention on physical health or falls , but patients in the exercise group were at increased risk of musculoskeletal injury ( risk ratio = 3.6 , 95 % confidence interval = 1.5 - 8.0 ) . Vitamin D supplementation did not improve physical performance , even in those who were vitamin D deficient ( < 12 ng/mL ) at baseline . CONCLUSION Neither vitamin D supplementation nor a home-based program of high-intensity quadriceps resistance exercise improved rehabilitation outcomes in frail older people after hospitalization . There was no effect of vitamin D on physical performance , and the exercises increased the risk of musculoskeletal injury . These findings do not support the routine use of these interventions at these dosages in the rehabilitation of frail older people 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 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: Dietary recommendations and r and omized trials on vitamin D supplementation should evaluate whether increases in circulating 25-hydroxyvitamin D levels match expectations -- for instance , the average increases obtained by trials on vitamin D3 without concomitant calcium supplements
background: CONTEXT Few studies in subjects over 50 yr of age have evaluated the influence of variable doses of vitamin D supplementation on serum 25-hydroxyvitamin D levels .
  OBJECTIVE We performed a meta- analysis of changes in circulating 25-hydroxyvitamin D level associated with vitamin D supplementation in Caucasian subjects over 50 yr old .