title: Association between vitamin D receptor gene polymorphisms, falls, balance and muscle power: results from two independent studies (APOSS and OPUS) Effect of vitamin D supplementation alone on muscle function in postmenopausal women: a randomized, double-blind, placebo-controlled clinical trial Combination of alfacalcidol and calcium improved handgrip strength and mobility among Indonesian older women: A randomized controlled trial The efficacy and safety of calcitriol and/or Caltrate D in elderly Chinese women with low bone mass Effects of Alfacalcidol on Back Extensor Strength Gained Through Back Extensor Exercise in Postmenopausal Women with Osteoporosis Physical performance and life quality in postmenopausal women supplemented with vitamin D: a two-year prospective study Muscle strength and mobility in vitamin D-insufficient female geriatric patients: a randomized controlled trial on vitamin D and calcium supplementation 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. Effects of three-monthly oral 150,000 IU cholecalciferol supplementation on falls, mobility, and muscle strength in older postmenopausal women: a randomized controlled trial. Effects of vitamin D and calcium supplementation on falls: a randomized controlled trial. Calcifediol versus vitamin D3 effects on gait speed and trunk sway in young postmenopausal women: a double-blind randomized controlled trial Eldecalcitol improves muscle strength and dynamic balance in postmenopausal women with osteoporosis: an open-label randomized controlled study A parallel group double-blind RCT of vitamin D3 assessing physical function: is the biochemical response to treatment affected by overweight and obesity? Treatment of Vitamin D Insufficiency in Postmenopausal Women: A Randomized Clinical Trial. A randomized controlled trial of the effects of vitamin D on muscle strength and mobility in older women with vitamin D insufficiency. Stronger back muscles reduce the incidence of vertebral fractures: a prospective 10 year follow-up of postmenopausal women. The 2011 Report on Dietary Reference Intakes for Calcium and Vitamin D from the Institute of Medicine: What Clinicians Need to Know Long-term effects of functional impairment on fracture risk and mortality in postmenopausal women Calcium, vitamin D supplementation, and physical function in the Women's Health Initiative. Effects of Vitamin D3 Supplementation on Muscle Strength, Mass, and Physical Performance in Women with Vitamin D Insufficiency: A Randomized Placebo-Controlled Trial The effect of vitamin D2 supplementation on muscle strength in early postmenopausal women: a randomized, double-blind, placebo-controlled trial Levels of serum sclerostin, FGF-23, and intact parathyroid hormone in postmenopausal women treated with calcitriol A randomized double-blinded placebo controlled trial of ergocalciferol 40,000 versus 100,000 IU per week for vitamin D inadequacy in institutionalized postmenopausal women Exercise and vitamin D in fall prevention among older women: a randomized clinical trial. Oral supplementation with 25(OH)D3 versus vitamin D3: effects on 25(OH)D levels, lower extremity function, blood pressure, and markers of innate immunity. Effects of Vitamin D3 Supplementation on Lean Mass, Muscle Strength, and Bone Mineral Density During Weight Loss: A Double-Blind Randomized Controlled Trial. A randomized study on the effect of vitamin D₃ supplementation on skeletal muscle morphology and vitamin D receptor concentration in older women.
abstract: Summary Fall prevention is a key strategy for reducing  osteoporotic fractures . We investigated the association between vitamin D receptor ( VDR ) polymorphisms and reported  falls in postmenopausal women . Bsm1 polymorphisms were associated with falls , balance and muscle power measurements . These results may explain some of the excess fracture risk associated with VDR in some studies . Introduction Fall prevention is a key strategy for reducing osteoporotic fractures . It has been suggested that vitamin D supplementation may reduce the incidence of falls by reducing body sway and increasing muscle power . The vitamin D receptor gene is a well-studied c and i date gene for osteoporosis . We investigated the association between VDR polymorphisms and reported  falls in postmenopausal women . Methods Falls data were collected in two separate population cohorts . Five polymorphisms of the VDR gene were analysed ( Cdx-2 , Fok-1 , BsmI , Taq1 and Apa1 ) in the Aberdeen Prospect i ve Osteoporosis Screening Study ( APOSS ) cohort . Results found in APOSS were then vali date d in an independent cohort — the Osteoporosis and Ultrasound ( OPUS ) study ( Bsm1 and Fok1 only ) , where muscle power and balance were also measured . Results Carriers of the ‘ B ’ allele ( Bsm1 ) showed an increased risk for falls . In APOSS , this was statistically significant for visit 3 multiple falls ( p = 0.047 ) and for recurrent falls ( p = 0.043 ) . Similar results were found in OPUS for visit 1 falls ( p = 0.025 ) and visit 1 multiple falls ( p = 0.015 ) . Bsm1 polymorphisms were also associated with balance and muscle power measurements . Conclusions In conclusion , these results demonstrate an association between the Bsm1 polymorphism and risk of falling that may explain some of the excess fracture risk associated with VDR in some studies Summary The present study investigates the effects of vitamin D on muscle function in postmenopausal women . It has been shown that vitamin D supplementation in postmenopausal women with hypovitaminosis D provides significant protective factor against sarcopenia , with significant increases in muscle strength and control of progressive loss of lean mass . Introduction We aim ed to evaluate the effect of supplementation of vitamin D ( VITD ) alone on muscle function in younger postmenopausal women . Methods In this double-blind , placebo-controlled clinical trial , 160 Brazilian postmenopausal women were r and omized into two groups : VITD group consisting of patients receiving vitamin D3 1000 IU/day orally ( n = 80 ) or placebo group ( n = 80 ) . Women with amenorrhea for more than 12 months and age 50–65 years , with a history of falls ( previous 12 months ) , were included . The intervention time was 9 months , with assessment s at two points , start and end . Lean mass was estimated by total-body dual-energy X-ray absorptiometry ( DXA ) and muscle strength by h and grip strength and chair rising test . The plasma concentrations of 25-hydroxyvitamin D [ 25(OH)D ] were measured by high-performance liquid chromatography ( HPLC ) . Statistical analysis was by intention to treat ( ITT ) , using ANOVA , Student ’s t test , and Tukey ’s test . Results After 9 months , average values of 25(OH)D increased from 15.0 ± 7.5 to 27.5 ± 10.4 ng/ml ( + 45.4 % ) in the VITD group and decreased from 16.9 ± 6.7 to 13.8 ± 6.0 ng/ml ( −18.5 % ) in the placebo group ( p < 0.001 ) . In the VITD group , there was significant increase in muscle strength ( + 25.3 % ) of the lower limbs by chair rising test ( p = 0.036 ) . In women in the placebo group , there was considerable loss ( −6.8 % ) in the lean mass ( p = 0.030 ) . Conclusion The supplementation of vitamin D alone in postmenopausal women provided significant protective factor against the occurrence of sarcopenia , with significant increases in muscle strength and control of progressive loss of lean mass AIM To determine the effect of alfacalcidol on muscle strength and functional mobility in Indonesian older women whose h and grip strength was low . METHODS A r and omized , double-blind controlled trial was carried out among 95 older women whose h and grip strength was ≤22 kg . Participants were r and omized into two groups : 47 participants received alfacalcidol 0.5 μg/day and 48 participants received a placebo . Each participant in both groups was given calcium 500 mg/day . H and grip strength as well as the Timed-Up and Go test were measured before and after 90 days of intervention . Per protocol analysis after intervention between two groups was carried out . RESULTS There was a significant improvement of h and grip strength in the group that received alfacalcidol compared with the placebo group ( 15.50 vs 13.75 ; P = 0.003 ) . The median time for the Timed-Up and Go test in the alfacalcidol group also improved significantly compared with the placebo group ( 9.01 vs 10.07 , P = 0.028 ) . CONCLUSIONS Alfacalcidol with daily doses of 0.5 μg significantly improved muscle strength and functional mobility in Indonesian older women . Geriatr Gerontol Int 2018 ; 18 : 434 - 440 Abstract Aim : To observe the efficacy and safety of Rocaltrol ( calcitriol ) and /or Caltrate D ( calicum carbonate plus vitamin D ) in elderly Chinese women with osteopenia or osteoporosis . Methods : One hundred fifty Chinese women aged over 65 years with osteopenia or osteoporosis from three centers were r and omly divided into two groups . Seventy-six participants received Caltrate D as one pill daily ; the other 74 participants received 0.25 μg Caltrate D plus Rocaltrol daily . The changes in bone mineral density ( BMD ) served as primary end-points . Height changes , the presence of new vertebral fractures , muscle strength and balance were evaluated . Results : The following are the mean percentage changes ( and SD ) in BMD over 12 months : at L2-L4 , 0.83±3.88 in the Caltrate D group and 2.84±4.04 in the Rocaltrol+Caltrate D group ( P=0.003 , by ANCOVA ) ; at the femoral neck , 0.04±3.94 in the Caltrate D group and 2.01±5.45 in the Rocaltrol+Caltrate D group ( P=0.085 , by ANCOVA ) ; and in the trochanter , 1.59±4.57 in the Caltrate D group and 3.76±6.25 in the Rocaltrol+Caltrate D group ( P=0.053 , by ANCOVA ) . The st and and maximal forward reach test ( SMFRT ) was significantly enhanced in both groups during the 12 months of treatment , but no significant differences were found between these two groups . No severe adverse event related to these medications occurred throughout the study . Conclusion : Treatment with Rocaltrol plus Caltrate D or Caltrate D for 12 months in elderly Chinese postmenopausal women  effectively increased BMD at the lumbar spine . Rocaltrol plus Caltrate D was more effective at the lumbar spine than Caltrate D alone Objective The aim of this study was to investigate the additive effect of the active form of vitamin D3 on the gain in back extensor strength through a back extensor exercise . Design A total of 107 postmenopausal women with osteoporosis were r and omly divided into two groups : the D3 group and the control group . Both groups were treated with calcium and alendronate and undertook the back extensor exercise . Alfacalcidol was prescribed only to the D3 group . Results There was no significant difference in the demographic data between the two groups . Ninety-four participants who completed a 4-mo intervention were subjected to per- protocol analysis . There was no significant difference in the improvement in back extensor strength between two the groups ( P = 0.349 ) . All subjects were further categorized into two subgroups by age . In the older subgroup ( ≥68 yrs ) , no significant difference was found in the improvement in back extensor strength ( P = 0.316 ) . In the younger subgroup ( < 68 yrs ) , the back extensor strength in the D3 group was significantly more improved than in the control group ( P = 0.034 ) . Conclusions The results of this study suggest that the administration of the active form of vitamin D3 enhances the beneficial effects of the back extensor exercise in patients younger than those in their late 60s Aim : To investigate the effects of calcium and vitamin D supplementation on bone turnover marker levels , muscle strength and quality of life in postmenopausal Chinese women . Methods : A total of 485 healthy postmenopausal Chinese women ( 63.44±5.04 years ) were enrolled in this open-label , 2-year , prospect i ve , community-based trial . The participants were divided into group A , B , C , which were treated with calcium ( 600 mg/d ) alone , calcium ( 600 mg/d ) and cholecalciferol ( 800 IU/d ) or calcium ( 600 mg/d ) and calcitriol ( 0.25 μg/d ) , respectively , for 2 years . Serum levels of 25-hydroxyvitamin D , parathyroid hormone , β-CTX and P1NP were measured , and the muscle strength and quality of life were assessed at baseline and at 12- and 24-month follow-ups . Results : Four hundred and sixty one participants completed this study . Serum levels of 25-hydroxyvitamin D were significantly increased in group C , but not changed in groups A and B at 24-month follow-up . Serum levels of parathyroid hormone , bone turnover marker β-CTX and bone formation marker P1NP were significantly decreased in group C , while serum levels of β-CTX were increased in group A at 24-month follow-up . The participants in group C maintained the grip strength , while those in groups A and B exhibited decreased grip strength at 24-month follow-up . The quality of life for the participants in groups B and C remained consistent , but that in group A was deteriorated at 24-month follow-up . Conclusion : Supplementation with calcitriol and calcium modifies the bone turnover marker levels , and maintains muscle strength and quality of life in postmenopausal Chinese women , whereas supplementation with cholecalciferol and calcium prevents aging-mediated deterioration in quality of life Background and aims : Insufficient vitamin D status , commonly found in older people , has been associated with muscle weakness which , in old age , impairs mobility and is a risk factor for falling . In a r and omized , double-blind placebo-controlled trial , we tested the hypothesis that vitamin D + calcium supplementation improves muscle strength and mobility , compared with calcium mono-therapy in vitamin D-insufficient female geriatric patients . Methods : Seventy female geriatric patients > 65 years of age with serum 25-hydroxyvitamin D3 ( 25OHD ) concentrations between 20 and 50 nmol/L , visiting an outpatient geriatric department , were included . Participants received either cholecalciferol 400 IU/day + calcium 500 mg/day ( D/Cal group ) or a placebo + calcium 500 mg/day ( Plac/Cal group ) for 6 months . At baseline and 6 months , muscle strength , power and functional mobility were tested . Results : At baseline , 25OHD was significantly ( p<0.05 ) associated with knee extension strength ( r=0.42 ) , h and grip strength ( r=0.28 ) , leg extension power ( r=0.34 ) , Timed Get Up and Go ( r=−0.31 ) and Modified Cooper test ( r=0.44 ) . At 6 months , a significant difference in 25OHD ( 77.2 vs 41.6 nmol/L , p<0.001 ) and 1,25OHD was found between the two groups . Significantly improving vitamin D status in the D/Cal group compared with the Plac/Cal group did not result in a significant difference in strength or functional mobility between the two groups . Conclusions : Daily 400IU vitamin D + 500 mg calcium supplementation is not enough to significantly improve strength or mobility in vitamin D-insufficient female geriatric patients 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 Daily vitamin D in addition to calcium supplementation reduces falls and fractures in older women . However , poor adherence to therapy is a common clinical problem . To examine the effects of supervised oral 3-monthly vitamin D therapy on falls , muscle strength , and mobility , we conducted a 9-month r and omized , double-blind , placebo-controlled trial in 686 community-dwelling ambulant women aged over 70 years . Participants received either oral cholecalciferol 150,000 IU every 3 months ( n = 353 ) or an identical placebo ( n = 333 ) . All participants were advised to increase dietary calcium intake . Falls data were collected 3-monthly . At baseline , 3 , 6 , and 9 months , muscle strength was measured by a h and held dynamometer and mobility by the Timed Up and Go ( TUG ) test . Serum 25 hydroxyvitamin D ( 25OHD ) was measured in a subgroup of 40 subjects . Mean age at baseline was 76.7 ± 4.1 years . The average serum 25OHD value at baseline was 65.8 ± 22.7 nmol/L. By 3 , 6 , and 9 months after supplementation , 25OHD levels of the vitamin D group were approximately 15 nmol/L higher than the placebo group . Calcium intake did not change significantly between baseline ( 864 ± 412 mg/day ) and 9 months ( 855 ± 357 mg/day ) . Faller rates in the two groups did not differ : vitamin D group , 102 of 353 ( 29 % ) ; placebo group , 89 of 333 ( 27 % ) . At 9 months , compared to placebo or baseline , muscle strength , and TUG were not altered by vitamin D. In conclusion , oral cholecalciferol 150,000 IU therapy administered 3-monthly had neither beneficial nor adverse effects on falls or physical function . These data together with previous findings confirm that intermittent large doses of vitamin D are ineffective or have a deleterious effect on falls . Thus despite adherence issues with daily vitamin D replacement , an intermittent , high-dose vitamin D regimen can not be supported as a strategy to reduce falls and fractures Specific receptors for vitamin D have been identified in human muscle tissue . Cross-sectional studies show that elderly persons with higher vitamin D serum levels have increased muscle strength and a lower number of falls . We hypothesized that vitamin D and calcium supplementation would improve musculoskeletal function and decrease falls . In a double-blind r and omized controlled trial , we studied 122 elderly women ( mean age , 85.3 years ; range , 63 - 99 years ) in long-stay geriatric care . Participants received 1200 mg calcium plus 800 IU cholecalciferol ( Cal+D-group ; n = 62 ) or 1200 mg calcium ( Cal-group ; n = 60 ) per day over a 12-week treatment period . The number of falls per person ( 0 , 1 , 2 - 5 , 6 - 7 , > 7 falls ) was compared between the treatment groups . In an intention to treat analysis , a Poisson regression model was used to compare falls after controlling for age , number of falls in a 6-week pretreatment period , and baseline 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D serum concentrations . Among fallers in the treatment period , crude excessive fall rate ( treatment - pretreatment falls ) was compared between treatment groups . Change in musculoskeletal function ( summed score of knee flexor and extensor strength , grip strength , and the timed up&go test ) was measured as a secondary outcome . Among subjects in the Cal+D-group , there were significant increases in median serum 25-hydroxyvitamin D ( + 71 % ) and 1,25-dihydroxyvitamin D ( + 8 % ) . Before treatment , mean observed number of falls per person per week was 0.059 in the Cal+D-group and 0.056 in the Cal-group . In the 12-week treatment period , mean number of falls per person per week was 0.034 in the Cal+D-group and 0.076 in the Cal-group . After adjustment , Cal+D-treatment accounted for a 49 % reduction of falls ( 95 % CI , 14 - 71 % ; p < 0.01 ) based on the fall categories stated above . Among fallers of the treatment period , the crude average number of excessive falls was significantly higher in the Cal-group ( p = 0.045 ) . Musculoskeletal function improved significantly in the Cal+D-group ( p = 0.0094 ) . A single intervention with vitamin D plus calcium over a 3-month period reduced the risk of falling by 49 % compared with calcium alone . Over this short-term intervention , recurrent fallers seem to benefit most by the treatment . The impact of vitamin D on falls might be explained by the observed improvement in musculoskeletal function Summary In this double-blind RCT , 4-month treatment with calcifediol compared with vitamin D3  improved gait speed by 18 % among young postmenopausal women . Consistently , change in 25(OH)D blood levels over time were significantly correlated with improvement in gait speed in these women . No effect could be demonstrated for trunk sway . Introduction The aim of this study is to test the effect of calcifediol compared with vitamin D3 on gait speed and trunk sway . Methods Twenty healthy postmenopausal women with an average 25(OH)D level of 13.2 ng/ml ( SD = ±3.9 ) and a mean age of 61.5 years ( SD = ±7.2 ) were r and omized to either 20 μg of calcifediol or 20 μg ( 800 IU ) of vitamin D3 per day in a double-blind manner . At baseline and at 4 months of follow-up , the same physiotherapist blinded to treatment allocation tested 8-m gait speed and a body sway test battery ( Sway star pitch and roll angle plus velocity while walking 8 m , and st and ing on both legs on a hard and soft surface ) . All analyses adjusted for baseline measurement , age , and body mass index . Results Mean 25(OH)D levels increased to 69.3 ng/ml ( SD = ±9.5 ) in the calcifediol group and to 30.5 ng/ml ( SD = ±5.0 ) in the vitamin D3 group ( p < 0.0001 ) .  Women receiving calcifediol compared with vitamin D3 had an 18 % greater improvement in gait speed at 4-month follow-up ( p = 0.046 ) adjusting for baseline gait speed , age , and body mass index . Also , change in gait speed was significantly correlated with change in serum 25(OH)D concentrations ( r = 0.5 ; p = 0.04 ) . Across three tests of trunk sway , there were no consistent differences between groups and no significant correlation between change in 25(OH)D serum concentrations and change in trunk sway  . Conclusions Calcifediol  improved gait speed in early postmenopausal women  compared with vitamin D3 and change in 25(OH)D level was moderately correlated with improvement in gait speed . A benefit on trunk sway could not be demonstrated The antifracture efficacy of vitamin D in osteoporosis is due to its direct action on bones and indirect extraskeletal effects to prevent falls . Eldecalcitol is an analog of active vitamin D3 that improves bone mineral density and reduces the risk of osteoporotic fractures . However , the effects of eldecalcitol on muscle strength and static and dynamic postural balance are unclear . In this open-label r and omized controlled study , we assessed the effects of eldecalcitol on muscle strength and static and dynamic postural balance in 50 postmenopausal women ( mean age 74 years ) with osteoporosis treated with bisphosphonate . Participants were r and omly divided into a bisphosphonate group ( alendronate at 35 mg/week ; n = 25 ) or an eldecalcitol group ( eldecalcitol at 0.75 μg/day and alendronate at 35 mg/week ; n = 25 ) and were followed up for 6 months . Trunk muscle strength , including back extensor strength and iliopsoas muscle strength , was measured . Static st and ing balance was evaluated and the one leg st and ing test was performed to assess static postural balance . Dynamic sitting balance was evaluated and the 10-m walk test , functional reach test , and timed up and go test were performed to assess dynamic postural balance . At 6 months , there were no significant changes in any measure of muscle strength or balance in the bisphosphonate group , whereas eldecalcitol significantly increased back extensor strength ( p = 0.012 ) and iliopsoas muscle strength ( p = 0.035 ) . Eldecalcitol also significantly improved findings on the timed up and go test ( p = 0.001 ) and dynamic sitting balance ( p = 0.015 ) at 6 months . These results with eldecalcitol may have an impact on prevention of falls Summary Vitamin D may affect skeletal muscle function . In a double-blind , r and omised , placebo-controlled trial , we found that vitamin D3 supplementation ( 400 or 1,000 I.U. vs. placebo daily for 1 year with bimonthly study visits ) does not improve grip strength or reduce falls . Introduction This study aim ed to test the supplementation effects of vitamin D3 on physical function and examine associations between overweight/obesity and the biochemical response to treatment . Methods In a parallel group double-blind RCT , healthy postmenopausal women from North East Scotl and ( latitude—57 ° N ) aged 60–70 years ( body mass index ( BMI ) , 18–45 kg/m2 ) were assigned ( computer r and omisation ) to daily vitamin D3 ( 400 I.U. ( n = 102)/1,000 I.U. ( n = 101 ) ) or matching placebo ( n = 102 ) ( 97 , 96 and 100 participants analysed for outcomes , respectively ) from identical coded containers for 1 year . Grip strength ( primary outcome ) , falls , diet , physical activity and ultraviolet B radiation exposure were measured bimonthly , as were serum 25(OH)D , adjusted calcium ( ACa ) and phosphate . Fat/lean mass ( dual energy X-ray absorptiometry ) , anthropometry , 1,25-dihydroxyvitamin D and parathyroid hormone were measured at baseline and 12 months . Participants and research ers were blinded throughout intervention and analysis . Results Treatment had no effect on grip strength ( mean change (SD)/year = −0.5 ( 2.5 ) , −0.9 ( 2.7 ) and −0.4 ( 3.3 ) kg force for 400/1,000 I.U. vitamin D3 and placebo groups , respectively ( P = .10 , ANOVA ) ) or falls ( P = .65 , chi-squared test ) . Biochemical responses were similar across BMI categories ( < 25.25–29.99 , ≥30 kg/m2 ) with the exception of a small change at 12-months in serum ACa in overweight compared to non-overweight participants ( P = .01 , ANOVA ; 1,000 I.U. group ) . In the  placebo group , 25(OH)D peak concentration change ( winter to summer ) was negatively associated with weight ( r = −.268 ) , BMI ( r = −.198 ) , total ( r = −.278 ) and trunk fat mass ( r = −.251 ) , with total and trunk fat mass predictive of winter to summer 25(OH)D change ( P = .01/.004 respectively , linear regression ) . Conclusion We found no evidence of an improvement in physical function following vitamin D3 supplementation for 1 year 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 OBJECTIVES To evaluate the effects of vitamin D treatment on muscle strength and mobility in older women with vitamin D insufficiency . DESIGN One-year population -based , double-blind , r and omized , controlled trial . SETTING Perth , Australia ( latitude 32 ° S ) . PARTICIPANTS Three hundred two community-dwelling ambulant elderly women aged 70 to 90 with a serum 25-hydroxyvitamin D ( 25(OH)D ) concentration less than 24 ng/mL. INTERVENTION Vitamin D(2 ) 1,000 IU/d or identical placebo ; calcium citrate ( 1 g calcium/d ) in both groups . MEASUREMENTS Lower limb muscle strength and mobility as assessed using the Timed Up and Go Test ( TUAG ) . RESULTS At baseline , mean ± st and ard deviation serum 25(OH)D was 17.7 ± 4.2 ng/mL ; this increased to 24.0 ± 5.6 ng/mL in the vitamin D group after 1 year but remained the same in the placebo group . For hip extensor and adductor strength and TUAG , but not for other muscle groups , a significant interaction between treatment group and baseline values was noted . In those with baseline values in the lowest tertile , vitamin D  improved muscle strength and TUAG more than calcium alone ( mean ( st and ard error ) : hip extensors 22.6 % ( 9.5 % ) ; hip adductors 13.5 % ( 6.7 % ) , TUAG 17.5 % ( 7.6 % ) , P < .05 ) . Baseline 25(OH)D levels did not influence patient response to supplementation . CONCLUSION Vitamin D therapy was observed to increase muscle function in those who were the weakest and slowest at baseline . Vitamin D should be given to people with insufficiency or deficiency to improve muscle strength and mobility The long-term protective effect of stronger back muscles on the spine was determined in 50 healthy white postmenopausal women , aged 58 - 75 years , 8 years after they had completed a 2 year r and omized , controlled trial . Twenty-seven subjects had performed progressive , resistive back-strengthening exercises for 2 years and 23 had served as controls .  Bone mineral density , spine radiographs , back extensor strength , biochemical marker values , and level of physical activity were obtained for all subjects at baseline , 2 years , and 10 years . Mean back extensor strength ( BES ) in the back-exercise ( BE ) group was 39.4 kg at baseline , 66.8 kg at 2 years ( after 2 years of prescribed exercises ) , and 32.9 kg at 10 years ( 8 years after cessation of the prescribed exercises ) . Mean BES in the control ( C ) group was 36.9 kg at baseline , 49.0 kg at 2 years , and 26.9 kg at 10 years . The difference between the two groups was still statistically significant at 10 year follow-up ( p = 0.001 ) . The difference in bone mineral density , which was not significant between the two groups at baseline and 2 year follow-up , was significant at 10 year follow-up ( p = 0.0004 ) . The incidence of vertebral compression fracture was 14 fractures in 322 vertebral bodies examined ( 4.3 % ) in the C group and 6 fractures in 378 vertebral bodies examined ( 1.6 % ) in the BE group ( chi-square test , p = 0.0290 ) . The relative risk for compression fracture was 2.7 times greater in the C group than in the BE group . To our knowledge , this is the first study reported in the literature demonstrating the long-term effect of strong back muscles on the reduction of vertebral fractures in estrogen-deficient women This article summarizes the new 2011 report on dietary requirements for calcium and vitamin D from the Institute of Medicine ( IOM ) . An IOM Committee charged with determining the population needs for these nutrients in North America conducted a comprehensive review of the evidence for both skeletal and extraskeletal outcomes . The Committee concluded that available scientific evidence supports a key role of calcium and vitamin D in skeletal health , consistent with a cause- and -effect relationship and providing a sound basis for determination of intake requirements . For extraskeletal outcomes , including cancer , cardiovascular disease , diabetes , and autoimmune disorders , the evidence was inconsistent , inconclusive as to causality , and insufficient to inform nutritional requirements . R and omized clinical trial evidence for extraskeletal outcomes was limited and generally uninformative . Based on bone health , Recommended Dietary Allowances ( RDAs ; covering requirements of ≥97.5 % of the population ) for calcium range from 700 to 1300 mg/d for life-stage groups at least 1 yr of age . For vitamin D , RDAs of 600 IU/d for ages 1–70 yr and 800 IU/d for ages 71 yr and older , corresponding to a serum 25-hydroxyvitamin D level of at least 20 ng/ml ( 50 nmol/liter ) , meet the requirements of at least 97.5 % of the population . RDAs for vitamin D were derived based on conditions of minimal sun exposure due to wide variability in vitamin D synthesis from ultraviolet light and the risks of skin cancer . Higher values were not consistently associated with greater benefit , and for some outcomes U-shaped associations were observed , with risks at both low and high levels . The Committee concluded that the prevalence of vitamin D inadequacy in North America has been overestimated . Urgent research and clinical priorities were identified , including re assessment of laboratory ranges for 25-hydroxyvitamin D , to avoid problems of both undertreatment and overtreatment Summary Our findings imply that simple functional tests can predict both hip fracture risk and excess mortality in postmenopausal women . Since the tests characterize general functional capacity ( one-legged stance , squatting down , and grip strength ) , these simple measures should have clinical utility in the assessment of women at risk of falls and fragility fracture . Introduction Functional impairment is associated with the risk of fall , which is the leading cause of hip fracture . We aim ed to determine how clinical assessment s of functional impairment predict long-term hip fracture and mortality . Methods A population -based prospect i ve cohort involved 2815 Caucasian women with the average baseline age of 59.1 years . The mean follow-up time in 1994–2014 was 18.3 years . Three functional tests and their combinations assessed at baseline were treated as dichotomous risk factors : ( 1 ) inability to squat down and touch the floor ( SQ ) , ( 2 ) inability to st and on one leg for 10 s ( SOL ) , and ( 3 ) having grip strength ( GS ) within the lowest quartile ( ≤ 58 kPa , mean 45.6 kPa ) . Bone mineral density ( BMD ) at the proximal femur was measured by DXA . Fractures and deaths were verified from registries . Hazard ratios were determined by using Cox proportional models . Age , body mass index ( BMI ) , and BMD were included as covariates for fracture risk estimates . Age , BMI , and smoking were used for mortality . Results Altogether , 650 ( 23.1 % ) women had 718 follow-up fractures , including 86 hip fractures . The mortality during the follow-up was 16.8 % ( n = 473 ) . Half of the women ( 56.8 % , n = 1600 ) had none of the impairments and were regarded as the referent group . Overall , women with any of the three impairments ( 43.2 % , n = 1215 ) had higher risks of any fracture , hip fracture , and death , with hazard ratios ( HR ) of 1.3 ( ( 95 % CI ) 1.0–1.5 , p < 0.01 ) , 2.4 ( 1.5–3.4 , p < 0.001 ) , and 1.5 ( 1.3–1.8 , p < 0.001 ) , respectively . The strongest single predictor for hip fracture was failing to achieve a one-leg st and for 10 s ( prevalence 7.1 % , n = 200 ) , followed by inability to squat down ( 27.0 % , n = 759 ) and weak grip strength ( 24.4 % , n = 688 ) , with their respective HRs of 4.3 ( 2.3–8.0 , p < 0.001 ) , 3.1 ( 2.0–5.0 , p < 0.001 ) , and 2.0 ( 1.2–3.4 , p < 0.001 ) . In addition , age , lower BMD , BMI , and smoking were significant covariates . Conclusions These findings suggest that functional tests provide long-term prediction of fracture and death in postmenopausal women . Whether reversal of these impairments is associated with a reduction in adverse outcomes is an area for future trials OBJECTIVES The Women 's Health Initiative ( WHI ) r and omized trial of calcium/vitamin D supplementation found reduced bone loss with active treatment compared to placebo . Now we examine whether the treatment affected self-reported physical functioning and objective measures of physical functioning . DESIGN A r and omized , double-blind , placebo-controlled trial of 1,000 mg calcium carbonate plus 400 IU vitamin D(3 ) per day or matching placebo pills . SUBJECTS/ SETTING The study included 33,067 women ( 50 to 79 years old ) at 40 US study centers . MAIN OUTCOME MEASURES Physical functioning was assessed by question naire at enrollment in WHI , 1 year prior to calcium/vitamin D trial r and omization and at study close-out ( average follow-up 7.1 years ) . Objective physical performance and self-reported exercise measures were collected at WHI baseline ( 1 year prior to calcium/vitamin D enrollment ) and 2 years and 4 years after calcium/vitamin D trial enrollment in a sub sample ( n=3,137 ) . STATISTICAL ANALYSES PERFORMED Calcium/vitamin D effects were tested in unadjusted and interaction linear models for each of the physical function measures . Covariates were baseline total calcium intake , fracture risk score , treatment arm in the hormone therapy and dietary modification trials ( ie , active drug or placebo , low-fat diet intervention or usual diet , respectively ) and age . RESULTS Neither intention to treat nor high adherence analyses produced substantial effects of calcium/vitamin D  compared to placebo on physical functioning or performance . The interaction analyses also did not result in differences because of calcium/vitamin D. CONCLUSIONS As the first long-term r and omized trial to examine the effectiveness of calcium and vitamin D in protecting against decline of physical functioning in older women , the results did not support benefit Vitamin D insufficiency and hyperparathyroidism have been associated with reduced muscle strength , physical performance , postural stability , well-being , and quality of life . In a double-blinded , r and omized placebo-controlled trial , we aim ed to investigate effects of vitamin D3 supplementation on above-mentioned outcomes in healthy community-dwelling postmenopausal women with plasma levels of 25-hydroxyvitamin D ( 25(OH)D ) below < 50 nmol/l and high parathyroid hormone ( PTH ) levels . Participants ( N = 81 ) were 1:1 treated with vitamin D3  , 70 µg ( 2800 IU)/day or identical placebo for three months during wintertime ( 56 ° N ) . Vitamin D3 supplementation  increased levels of 25(OH)D and 1,25(OH)2D by 230 % ( 95 % CI 189 to 272)% , p < 0.001 and 58 % ( 190 to 271 % ) , p < 0.001 , respectively , and reduced PTH by 17 % ( − 23 to − 11 % ) , p < 0.001 . Compared with placebo , vitamin D3 significantly reduced maximal h and grip strength by 9 % ( − 15 to − 3 % ; p < 0.01 ) and knee flexion strength by 13 % ( − 24 to − 2 % ; p = 0.02 ) and increased the time spent on performing the Timed Up and Go test by 4.4 % ; ( 0.1–8.6 % ; p < 0.05 ) . Levels of physical activity , total lean body mass , appendicular lean mass index , postural stability , well-being , and quality of life did not change in response to treatment . Compared with placebo , a daily supplement with a relatively high dose of vitamin D3 had no beneficial effects on any outcomes . In some measures of muscle strength and physical performance , we even saw a small unfavorable effect . Our data call for caution on use of relatively high daily doses of vitamin D3 in the treatment of vitamin D insufficiency Abstract Background : Low serum 25-hydroxyvitamin D [ 25(OH)D ] has been shown to be associated with low muscle mass and loss of muscle strength , result ing in increased disability and frailty in older men and women . Vitamin D deficiency is common in postmenopausal women . The primary objective of the present study was to evaluate the effects of vitamin D supplementation on muscle strength in early postmenopausal women . The effects of vitamin D2 supplementation on muscle mass and muscle cross-sectional area ( CSA ) were secondarily investigated . Methods : A 12-week , prospect i ve , r and omized , double-blind , placebo-controlled trial was conducted in early postmenopausal women ( 45–60 years old ) with vitamin D deficiency ( serum 25(OH)D < 20 ng/ml ) . A total of 88 subjects were r and omized into group I : vitamin D2 supplement 40 000 IU/week ( n = 44 ) , or group II : placebo ( n = 44 ) . Serum 25(OH)D level , muscle strength , muscle mass and muscle CSA were assessed at baseline and 12 weeks after the supplementation . Results : After 12 weeks of supplementation , 70 % of women in group I achieved a sufficient level of serum 25(OH)D ( > 30 ng/ml ) . There were significant differences in changes of serum 25(OH)D levels between the two groups ( p < 0.05 ) . Muscle strength and muscle CSA in group I increased significantly after 12 weeks ( p = 0.015 , 0.045 , respectively ) . However , there were no significant differences in the mean changes of muscle strength , muscle mass and muscle CSA between the two groups ( p = 0.16 , 0.89 , 0.84 , respectively ) . Conclusion : In this study , we found no obvious effect of vitamin D supplementation on the changes in muscle strength , muscle mass and muscle CSA when compared to placebo . However , there were significant changes in muscle strength and muscle CSA from baseline in the vitamin D supplementation group Objective This study aim ed to determine the effect of calcitriol on serum concentrations of fibroblast growth factor-23 ( FGF-23 ) , sclerostin , intact parathyroid hormone ( PTH ) , and h and grip strength in postmenopausal women with low bone mass . Methods A r and omized , double-blind controlled trial was carried out among 141 postmenopausal women with low bone mass . Participants were r and omized into two groups : 75 participants received calcitriol 0.5 µg/day and 66 participants received a placebo for 12 weeks . Results After 12-week calcitriol treatment , significant decreases in serum intact PTH ( P=0.035 ) and sclerostin ( P=0.039 ) , as well as significant increases in serum creatinine ( P=0.027 ) , uric acid ( P=0.032 ) , 24-hour urinary calcium ( P=0.0026 ) , and left h and grip strength ( P=0.03 ) , were observed , compared to placebo group . Level of serum sclerostin was weakly but significantly positively correlated with serum PTH ( r=0.277 ; P=0.01 ) and negatively correlated with 24-hour urinary calcium ( r=−0.221 ; P=0.04 ) and left h and grip strength ( r=−0.338 ; P=0.03 ) after calcitriol treatment . Multiple regression analysis demonstrated that decrease in serum sclerostin was associated with decrease in PTH serum level  after calcitriol treatment ( OR , 7.90 ; 95 % CI , 2.28–27.42 ; P=0.002 ) . However , no significant change in FGF-23 level was observed after calcitriol treatment . Conclusion Calcitriol treatment yields a considerable decrease in serum sclerostin and significant increase of h and grip strength , and the change in serum sclerostin is regulated by serum PTH and by muscle strength Background Vitamin D inadequacy is common in institutionalized post-menopausal women who are at the highest risk for osteoporotic fracture . Aim To evaluate efficacy and safety of ergocalciferol 40,000 versus 100,000 IU per week for 12 weeks for vitamin D inadequacy in institutionalized postmenopausal women . Method A r and omized double-blinded placebo-controlled trial was conducted in 94 institutionalized subjects with baseline 25(OH)D levels < 30 ng/mL. Subjects were r and omized to receive ergocalciferol 40,000 ( st and ard dose ) or ergocalciferol 100,000 IU ( high dose ) per week . Serum 25(OH)D levels , calcium , phosphate , h and grip strength , time up and go ( TUG ) test and quality of life by EQ-5D-5L were measured at baseline and 12 weeks after r and omization . Results Of the 94 subjects enrolled , 85 subjects completed the study . Subjects in the high dose group had higher mean 25(OH)D levels than subjects in the st and ard group ( 51.73 ± 19.35 and 34.5 ± 9.12 , p < 0.001 ) . More subjects in the high dose group ( 90.9 % ) achieved optimal 25(OH)D levels ( > 30 ng/mL ) than those in the st and ard group ( 65.9 % ) , p = 0.007 . In a subgroup analysis of subjects with vitamin D deficiency ( < 20 ng/mL , n = 44 ) and severe vitamin D deficiency ( < 10 ng/mL , n = 9 ) , more subjects in the high dose group achieved optimal 25(OH)D levels than those in the st and ard group ( 88 % and 100 % versus 47.4 % and 16.7 % with p of 0.007 and 0.018 , respectively ) . There were no differences in h and grip strength , TUG , EQ-5D-5L and adverse events between groups . Discussion / conclusions Subjects who received high dose ergocalciferol achieved more optimal 25(OH)D levels than those who received st and ard dose . High dose ergocalciferol is preferred to optimize 25(OH)D levels in subjects with severe vitamin D deficiency IMPORTANCE While vitamin D supplementation and exercise are recommended for prevention of falls for older people , results regarding these 2 factors are contradictory . OBJECTIVE To determine the effectiveness of targeted exercise training and vitamin D supplementation in reducing falls and injurious falls among older women . DESIGN , SETTING , AND PARTICIPANTS A 2-year r and omized , double-blind , placebo-controlled vitamin D and open exercise trial conducted between April 2010 and March 2013 in Tampere , Finl and . Participants were 409 home-dwelling women 70 to 80 years old . The main inclusion criteria were at least 1 fall during the previous year , no use of vitamin D supplements , and no contraindication to exercise . INTERVENTIONS Four study groups , including placebo without exercise , vitamin D ( 800 IU/d ) without exercise , placebo and exercise , and vitamin D ( 800 IU/d ) and exercise . MAIN OUTCOMES AND MEASURES The primary outcome was monthly reported falls . Injurious falls and the number of fallers and injured fallers were reported as secondary outcomes . In addition , bone density , physical functioning ( muscle strength , balance , and mobility ) , and vitamin D metabolism were assessed . RESULTS Intent-to-treat analyses showed that neither vitamin D nor exercise reduced falls . Fall rates per 100 person-years were 118.2 , 132.1 , 120.7 , and 113.1 in the placebo without exercise , vitamin D without exercise , placebo and exercise , and vitamin D and exercise study groups , respectively ; however , injurious fall rates were 13.2 , 12.9 , 6.5 , and 5.0 , respectively . Hazard ratios for injured fallers were significantly lower among exercisers with vitamin D ( 0.38 ; 95 % CI , 0.17 - 0.83 ) and without vitamin D ( 0.47 ; 95 % CI , 0.23 - 0.99 ) . Vitamin D maintained femoral neck bone mineral density and increased tibial trabecular density slightly . However , only exercise improved muscle strength and balance .  Vitamin D did not enhance exercise effects on physical functioning . CONCLUSIONS AND RELEVANCE The rate of injurious falls and injured fallers more than halved with strength and balance training in home-dwelling older women , while neither exercise nor vitamin D affected the rate of falls . Exercise improved physical functioning . Future research is needed to determine the role of vitamin D in the enhancement of strength , balance , and mobility . TRIAL REGISTRATION clinical trials.gov Identifier : NCT00986466 To test the effect of 25(OH)D(3 ) ( HyD ) compared to vitamin D(3 )  on serum 25-hydroxyvitamin D levels ( 25(OH)D ) , lower extremity function , blood pressure , and markers of innate immunity . Twenty healthy postmenopausal women with an average 25(OH)D level of 13.2 ± 3.9 ng/mL ( mean ± SD ) and a mean age of 61.5 ± 7.2 years were r and omized to either 20 µg of HyD or 20 µg ( 800 IU ) of vitamin D(3 ) per day in a double-blind manner . We measured on 14 visits over 4 months , 25(OH)D serum levels , blood pressure , and seven markers of innate immunity ( eotaxin , interleukin [IL]-8 , IL-12 , interferon gamma-induced protein 10 kDa [ IP-10 ] , monocyte chemotactic protein-1 [ MCP-1 ] , macrophage inflammatory protein beta [ MIP-1β ] , and " Regulated upon Activation , Normal T-cell Expressed , and Secreted " [ RANTES ] ) . At baseline and at 4 months , a test battery for lower extremity function ( knee extensor and flexor strength , timed up and go , repeated sit-to-st and ) was assessed . All analyses were adjusted for baseline measurement , age , and body mass index . Mean 25(OH)D levels increased to 69.5 ng/mL in the HyD group . This rise was immediate and sustained . Mean 25(OH)D levels increased to 31.0 ng/mL with a slow increase in the vitamin D(3 ) group . Women on HyD compared with vitamin D(3 ) had a 2.8-fold increased odds of maintained or improved lower extremity function ( odds ratio [ OR ] = 2.79 ; 95 % confidence interval [ CI ] , 1.18 - 6.58 ) , and a 5.7-mmHg decrease in systolic blood pressure ( p = 0.0002 ) . Both types of vitamin D contributed to a decrease in five out of seven markers of innate immunity , significantly more pronounced with HyD for eotaxin , IL-12 , MCP-1 , and MIP-1 β . There were no cases of hypercalcemia at any time point . Twenty micrograms ( 20 µg ) of HyD per day result ed in a safe , immediate , and sustained increase in 25(OH)D serum levels in all participants , which may explain its significant benefit on lower extremity function , systolic blood pressure , and innate immune response compared with vitamin D(3 ) OBJECTIVES To compare the effects of 12 months of vitamin D3 supplementation with that placebo on lean mass , bone mineral density ( BMD ) , and muscle strength in overweight or obese postmenopausal women completing a structured weight-loss program . DESIGN Double-blind , placebo-controlled r and omized clinical trial . SETTING Fred Hutchinson Cancer Research Center , Seattle , Washington . PARTICIPANTS Postmenopausal women aged 50 to 75 with a body mass index ( BMI ) of 25 kg/m(2 ) or greater and a serum 25-hydroxyvitamin D ( 25(OH)D ) concentration between 10.0 and 32.0 ng/mL ( insufficient ) ( N = 218 ) . INTERVENTION Oral vitamin D3 2,000 IU/d or placebo in combination with a lifestyle-based weight loss intervention consisting of a reduction of 500 kcal to 1,000 kcal per day and 225 min/wk of moderate- to vigorous-intensity aerobic exercise .  MEASUREMENTS Serum 25(OH)D , body composition , and muscle strength were measured before r and omization ( baseline ) and at 12 months . Mean changes of the groups were compared ( intention to treat ) using generalized estimating equations . RESULTS Change in 25(OH)D was significantly different between the vitamin D and placebo groups at 12 months ( 13.6 ng/mL vs -1.3 ng/mL , P < .001 ) , but no differences in change in lean mass ( -0.8 kg vs -1.1 kg , P = .53 ) or BMD of the spine ( -0.01 g/cm(2 ) vs 0.0 g/cm(2 ) , P = .82 ) or right femoral neck ( both -0.01 g/cm(2 ) , P = .49 ) were detected between the groups . Leg strength decreased in the vitamin D group but not in the placebo group ( -2.6 pounds vs 1.8 pounds , P = .03 ) . In women r and omized to vitamin D , achieving repletion ( 25(OH)D ≥ 32 ng/mL ) did not alter results . CONCLUSION Vitamin D3 supplementation during weight-loss decreased leg strength but did not alter changes in lean mass or BMD in postmenopausal women with vitamin D insufficiency CONTEXT Studies examining whether vitamin D supplementation increases muscle mass or muscle-specific vitamin D receptor ( VDR ) concentration are lacking . OBJECTIVE Our objective was to determine whether vitamin D₃ 4000 IU/d alters muscle fiber cross-sectional area ( FCSA ) and intramyonuclear VDR concentration over 4 months . DESIGN AND SETTING This was a r and omized , double-blind , placebo-controlled study in a single center . PARTICIPANTS Participants were 21 mobility-limited women ( aged ≥ 65 years ) with serum 25-hydroxyvitamin D ( 25OHD ) levels of 22.5 to 60 nmol/L. MAIN OUTCOME MEASURES Baseline and 4-month FCSA and intramyonuclear VDR were measured from vastus lateralis muscle cross-sections probed for muscle fiber type ( I/IIa/IIx ) and VDR using immunofluorescence . RESULTS At baseline , mean ( ±SD ) age was 78 ± 5 years ; body mass index was 27 ± 5 kg/m² , 25OHD was 46.3 ± 9.5 nmol/L , and  a short physical performance battery score was 7.95 ± 1.57 out of 12 . At 4 months , 25OHD level was 52.5 ± 17.1 ( placebo ) vs 80.0 ± 11.5 nmol/L ( vitamin D [ VD ] ; P < .01 ) , and change in 25OHD level was strongly associated with percent change in intramyonuclear VDR concentration-independent of group ( r = 0.87 , P < .001 ) . By treatment group , percent change in intramyonuclear VDR concentration was 7.8 % ± 18.2 % ( placebo ) vs 29.7 % ± 11.7 % ( VD ; P = .03 ) with a more pronounced group difference in type II vs I fibers . Percent change in total ( type I/II ) FCSA was -7.4 % ± 18.9 % ( placebo ) vs 10.6 % ± 20.0 % ( VD ; P = .048 ) . CONCLUSION Vitamin D₃ supplementation  increased intramyonuclear VDR concentration by 30 % and increased muscle fiber size by 10 % in older , mobility-limited , vitamin D-insufficient women . Further work is needed to determine whether the observed effect of vitamin D on fiber size is mediated by the VDR and to identify which signaling pathways are involved
target: The present review demonstrates that vitamin D supplementation result ed in small but nonsignificant improvements in muscle strength compared to control in postmenopausal women .
  No significant effect was observed in mobility after vitamin D administration
background: BACKGROUND The results obtained from previous trials regarding the effects of vitamin D supplementation on muscle strength and mobility  in postmenopausal women have been inconsistent .
  This systematic review and meta- analysis of r and omised controlled trials ( RCTs ) aim ed to investigate the effect of vitamin D supplementation on muscle strength and mobility in postmenopausal women .