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 Acute Effects of Vitamin D3 Supplementation on Muscle Strength in Judoka Athletes: A Randomized Placebo-Controlled, Double-Blind Trial Influence of vitamin D mushroom powder supplementation on exercise-induced muscle damage in vitamin D insufficient high school athletes Effects of Vitamin D3 Supplementation on Muscle Strength, Mass, and Physical Performance in Women with Vitamin D Insufficiency: A Randomized Placebo-Controlled Trial Effects of a multi-component exercise program and calcium–vitamin-D3-fortified milk on bone mineral density in older men: a randomised controlled trial The effects of vitamin D3 supplementation on serum total 25[OH]D concentration and physical performance: a randomised dose–response study Effects of Vitamin D3 Supplementation on Lean Mass, Muscle Strength, and Bone Mineral Density During Weight Loss: A Double-Blind Randomized Controlled Trial. Skeletal site-dependent response of bone mineral density and quantitative ultrasound parameters following a 12-month dietary intervention using dairy products fortified with calcium and vitamin D: the Postmenopausal Health Study. Effects of vitamin D supplementation on neuroplasticity in older adults: a double-blinded, placebo-controlled randomised trial The skeletal benefits of calcium- and vitamin D3-fortified milk are sustained in older men after withdrawal of supplementation: an 18-mo follow-up study. Calcium- and vitamin D3-fortified milk reduces bone loss at clinically relevant skeletal sites in older men: a 2-year randomized controlled trial. A parallel group double-blind RCT of vitamin D3 assessing physical function: is the biochemical response to treatment affected by overweight and obesity? Correcting Vitamin D Insufficiency Improves Some But Not All Aspects of Physical Performance During Winter Training in Taekwondo Athletes. 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 vitamin D3 supplementation on relapses, disease progression, and measures of function in persons with multiple sclerosis: exploratory outcomes from a double-blind randomised controlled trial The role of vitamin D in improving physical performance in the elderly.
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 Objective : Indoor athletes have been shown to be prone to vitamin D3 deficiency . The aim of the study was to examine the acute effects of vitamin D supplementation on muscle function using isokinetic dynamometry . Design : R and omized placebo-controlled , double-blind study . Setting : Institutional . Participants : Adult male white national level judoka athletes ( n = 22 ) who were involved in full-time training . Exclusion criteria were vitamin supplementation , overseas travel to sunny climes , and /or an injury incurred during the last 3 months before testing . Interventions : Subjects were r and omly allocated to the treatment ( 150 000IU vitamin D3 ) or placebo and given blinded supplements by an independent research er . Participants were tested twice , 8 days apart , on a Monday morning before the start of judo training and after 2 days of rest . A 5 to 7 mL of blood sample was collected followed by isokinetic concentric quadriceps and hamstring muscle function assessment s on the right leg at 30 and 200 ° ·s−1 . Main Outcome Measures : Repeated- measures analysis of variance was used to analyze isokinetic muscle force and serum 25(OH)D3 . Regression to the mean was used to examine changes in 25(OH)D3 levels over the study period . Results : The treatment group demonstrated a significant increase in serum 25(OH)D levels ( 34 % , P ⩽ 0.001 ) and muscle strength ( 13 % , P = 0.01 ) between days 1 and 8 . No significant differences were found for the placebo group for the same period . Conclusions : A single bolus of 150 000IU vitamin D3 had a significant positive effect on serum 25(OH)D levels and muscle function in vitamin D insufficient elite indoor athletes . Clinical Relevance : Serum 25(OH)D3 levels of indoor athletes should be monitored throughout the year and especially during winter months . Beneficial responses , in muscle strength and serum 25(OH)D3 , to 1 dose of vitamin D3 supplementation can be observed within 1 week of ingestion . Muscle strength is linked to serum 25(OH)D levels Abstract Incidence of vitamin D deficiency is increasing worldwide . The purpose of this study was to determine if supplementation with vitamin D2 from Portobello mushroom powder would enhance skeletal muscle function and attenuate exercise-induced muscle damage in low vitamin D status high school athletes . Participants were r and omised to Portobello mushroom powder ( 600 IU/d vitamin D2 ) or placebo for 6 weeks . Participants then completed a 1.5-h exercise session design ed to induce skeletal muscle damage . Blood sample s and measures of skeletal muscle function were taken pre-supplementation , post-supplementation/pre-exercise and post-exercise . Six weeks supplementation with vitamin D2 increased serum 25(OH)D2 by 9.9-fold and decreased serum 25(OH)D3 by 28 % . Changes in skeletal muscle function and circulating markers of skeletal muscle damage did not differ between groups . In conclusion , 600 IU/d vitamin D2 increased 25(OH)D2 with a concomitant decrease in 25(OD)D3 , with no effect on muscular function or exercise-induced muscle damage in high school athletes 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 Summary We examined the independent and combined effects of a multi-component exercise program and calcium – vitamin-D3-fortified milk on bone mineral density ( BMD ) in older men .  Exercise result ed in a 1.8 % net gain in femoral neck BMD , but additional calcium – vitamin D3 did not enhance the response in this group of older well-nourished men . Introduction This 12-month r and omised controlled trial assessed whether calcium – vitamin-D3-fortified milk could enhance the effects of a multi-component exercise program on BMD in older men . Methods Men ( n = 180 ) aged 50–79 years were r and omised into : ( 1 )  exercise + fortified milk ; ( 2 ) exercise ; ( 3 ) fortified milk ; or ( 4 ) controls . Exercise consisted of high intensity progressive resistance training with weight-bearing impact exercise . Men assigned to fortified milk consumed 400 mL/day of low fat milk providing an additional 1,000 mg/day calcium and 800 IU/day vitamin D3 . Femoral neck ( FN ) , total hip , lumbar spine and trochanter BMD and body composition ( DXA ) , muscle strength 25-hydroxyvitamin D and parathyroid hormone ( PTH ) were assessed . Results There were no exercise-by-fortified milk interactions at any skeletal site . Exercise result ed in a 1.8 % net gain in FN BMD relative to no-exercise ( p < 0.001 ) ; lean mass ( 0.6 kg , p < 0.05 ) and muscle strength ( 20–52 % , p < 0.001 ) also increased in response to exercise . For lumbar spine BMD , there was a net 1.4–1.5 % increase in all treatment groups relative to controls ( all p < 0.01 ) . There were no main effects of fortified milk at any skeletal site . Conclusion A multi-component community-based exercise program was effective for increasing FN BMD in older men , but additional calcium – vitamin D3 did not enhance the osteogenic response 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 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 The aim of the current study was to examine whether calcium supplementation could prevent bone loss in postmenopausal women or more favourable outcomes could be obtained via the consumption of dairy products fortified with calcium and vitamin D3 . For this purpose changes in bone mineral density ( BMD ) at different skeletal sites , assessed by dual-energy X-ray absorptiometry , as well as in quantitative ultrasound ( QUS ) parameters of the calcaneus over 12 months were estimated . A population of 101 postmenopausal women ( 55 - 65 years old ) was r and omized into a dairy group ( DG : n 39 ) , receiving approximately 1200 mg calcium/d and 7.5 microg vitamin D3/d through fortified dairy products ; a calcium-supplemented group ( CaG : n 26 ) provided with a calcium supplement of 600 mg/d ; and a control group ( CG : n 36 ) . Over the intervention period the DG was found to have more favourable changes in pelvis ( P=0.040 ) , total spine ( P<0.001 ) and total body BMD ( P<0.001 ) than the other groups . A significant increase was also observed for DG in lumbar spine BMD ( 2.0 % ; 95 % CI 0.5 , 3.5 ) although it did not differentiate significantly compared to the other groups . No significant differences were observed with respect to the changes in QUS parameters . The current study revealed that recommended intakes of vitamin D3 and calcium via fortified dairy products for 12 months can induce favourable changes in pelvis , total spine and total body BMD in postmenopausal women but not in QUS parameters . No such favourable changes were observed via supplementation of calcium alone Summary Vitamin D can improve muscle function and reduce  falls  , but whether it can strengthen neural connections within the brain and nervous system is not known . This 10-week r and omised controlled trial indicates that treatment with 2,000 IU/day vitamin D3 does not significantly alter neuroplasticity relative to placebo in older adults . Introduction The purpose of this study was to examine the effects of vitamin D supplementation on neuroplasticity , serum brain-derived neurotrophic factor ( BDNF ) and muscle strength and function in older adults . Methods This was a 10-week double-blinded , placebo-controlled r and omised trial in which 26 older adults with 25-hydroxyvitamin D [ 25OHD ] concentrations 25–60 nmol/L were r and omised to 2,000 IU/day vitamin D3 or matched placebo .  Single- and paired-pulse transcranial magnetic stimulation applied over the motor cortex was used to assess changes in motor-evoked potentials ( MEPs ) and short-interval intracortical inhibition ( SICI ) , as measures of corticospinal excitability and inhibition respectively , by recording electromyography ( EMG ) responses to stimulation from the wrist extensors . Changes in muscle strength , stair climbing power , gait ( timed-up- and -go ) , dynamic balance ( four square step test ) , serum 25(OH)D and BDNF concentrations were also measured . Results After 10 weeks , mean 25(OH)D levels increased from 46 to 81 nmol/L in the vitamin D group with no change in the placebo group . The vitamin D group experienced a significant 8–11 % increase in muscle strength and a reduction in cortical excitability ( MEP amplitude ) and SICI relative to baseline ( all P < 0.05 ) , but these changes were not significantly different from placebo . There was no effect of  vitamin D  on muscle power , function or BDNF . Conclusions Daily supplementation with 2,000 IU vitamin D3 for 10 weeks had no significant effect on neuroplasticity compared to placebo , but the finding that vitamin D treatment alone was associated with a decrease in corticospinal excitability and intracortical inhibition warrants further investigation as this suggests that it may improve the efficacy of neural transmission within the corticospinal pathway BACKGROUND In a previous 2-y r and omized controlled trial , we showed that calcium- and vitamin D3-fortified milk stopped or slowed bone loss at several clinical ly relevant skeletal sites in older men . OBJECTIVE The present study aim ed to determine whether the skeletal benefits of the fortified milk were sustained after withdrawal of the supplementation . DESIGN One hundred nine men > 50 y old who had completed a 2-y fortified milk trial were followed for an additional 18 mo , during which no fortified milk was provided . Bone mineral density ( BMD ) of the total hip , femoral neck , lumbar spine , and forearm was measured by using dual-energy X-ray absorptiometry . RESULTS Comparison of the mean changes from baseline between the groups ( adjusted for baseline age , BMD , total calcium intake , and change in weight ) showed that the net beneficial effects of fortified milk on femoral neck and ultradistal radius BMD at the end of the intervention ( 1.8 % and 1.5 % , respectively ; P < 0.01 for both ) were sustained at 18-mo follow-up ( P < 0.05 for both ) . The nonsignificant between-group differences at the total hip ( 0.8 % ; P = 0.17 ) also persisted at follow-up ( 0.7 % ; P = 0.10 ) , but there were no lasting benefits at the lumbar spine . The average total dietary calcium intake in the milk supplementation group at follow-up approximated recommended amounts for Australian men > 50 y old ( 1000 mg/d ) but did not differ significantly from that in the control subjects ( 1021 versus 890 mg/d ) . CONCLUSION Supplementation with calcium- and vitamin D3-fortified milk for 2 y may provide some sustained benefits for BMD  in older men after withdrawal of supplementation UNLABELLED In this 2-year r and omized controlled study of 167 men > 50 years of age , supplementation with calcium-vitamin D3-fortified milk providing an additional 1000 mg of calcium and 800 IU of vitamin D3 per day was effective for suppressing PTH and stopping or slowing bone loss at several clinical ly important skeletal sites at risk for fracture . INTRODUCTION Low dietary calcium and inadequate vitamin D stores have long been implicated in age-related bone loss and osteoporosis . The aim of this study was to assess the effects of calcium and vitamin D3 fortified milk on BMD in community living men > 50 years of age . MATERIAL S AND METHODS This was a 2-year r and omized controlled study in which 167 men ( mean age + /- SD , 61.9 + /- 7.7 years ) were assigned to receive either 400 ml/day of reduced fat ( approximately 1 % ) ultra-high temperature ( UHT ) milk containing 1000 mg of calcium plus 800 IU of vitamin D3 or to a control group receiving no additional milk . Primary endpoints were changes in BMD , serum 25(OH)D , and PTH . RESULTS One hundred forty-nine men completed the study . Baseline characteristics between the groups were not different ; mean dietary calcium and serum 25(OH)D levels were 941 + /- 387 mg/day and 77 + /- 23 nM , respectively . After 2 years , the mean percent change in BMD was 0.9 - 1.6 % less in the milk supplementation compared with control group at the femoral neck , total hip , and ultradistal radius ( range , p < 0.08 to p < 0.001 after adjusting for covariates ) . There was a greater increase in lumbar spine BMD in the milk supplementation group after 12 and 18 months ( 0.8 - 1.0 % , p < or = 0.05 ) , but the between-group difference was not significant after 2 years ( 0.7 % ; 95 % CI , -0.3 , 1.7 ) . Serum 25(OH)D increased and PTH decreased in the milk supplementation relative to control group after the first year ( 31 % and -18 % , respectively ; both p < 0.001 ) , and these differences remained after 2 years . Body weight remained unchanged in both groups at the completion of the study . CONCLUSIONS Supplementing the diet of men > 50 years of age with reduced-fat calcium- and vitamin D3-enriched milk may represent a simple , nutritionally sound and cost-effective strategy to reduce  age-related bone loss  at several skeletal sites at risk for fracture in the elderly 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 We investigated the effects of vitamin D3 supplementation on physical performance during winter training in vitamin D insufficient taekwondo athletes . Thirty-five collegiate male and female taekwondo athletes , aged 19 - 22 years with low serum 25(OH)D concentration ( 28.8 ± 1.10 nmol/L ) , were r and omly assigned to a vitamin D group ( n = 20 ) or a placebo group ( n = 15 ) . Subjects received either a vitamin D3 capsule ( 5,000 IU/day ) or a placebo during 4 weeks of winter training . Blood sample s were collected for analyzing serum 25(OH)D concentration . Physical performance tests included Wingate anaerobic test , isokinetic muscle strength and endurance , a countermovement jump test , sit-ups , agility test , and 20-m pacer . Serum 25(OH)D concentrations increased significantly in the vitamin D group ( 96.0 ± 3.77 nmol/L ) after 4 weeks of supplementation , but no changes were found in the placebo group ( F = 242.44 , p = .000 ) . There were significant interaction effects for anaerobic peak power ( F = 7.49 , p = .010 ) and isokinetic knee extension at 180 deg/s ( F = 6.08 , p = .019 ) . Changes in serum 25(OH)D concentration were positively associated with changes in peak power and isokinetic knee extension at 180 deg/s . However , no significant interaction effects were observed in other performance variables . This study suggests that 4 weeks of vitamin D supplementation elevates serum 25(OH)D concentration to sufficient levels . Correcting vitamin D insufficiency improves some but not all aspects of performance . Thus , efficacy of vitamin D supplementation to enhance performance remains unclear 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 Background : High vitamin D levels may reduce the risk of relapses and disease progression in multiple sclerosis . Methods : This 96-week r and omised controlled trial was design ed to assess the effect of vitamin D3 supplementation on bone mineral density in persons with multiple sclerosis . Supplementation with 20,000 IU vitamin D3 weekly raised median serum 25-hydroxy vitamin D ( 25[OH]D ) to 121 nmol/L. The modified intention to treat analysis included 35 persons in the vitamin D3 group and 33 in the placebo group . Participants were age 21 to 50 years and fully ambulatory ( median Exp and ed Disability Status Scale ( EDSS ) 2.5 ) . We studied the effect of supplementing vitamin D3 on the exploratory outcomes annualised relapse rate ( ARR ) , EDSS , multiple sclerosis functional composite ( MSFC ) components , grip strength , and fatigue . Results : After 96 weeks , there was no significant difference between groups in ARR ( absolute difference 0.10 , 95 % CI -0.07 to 0.27 ; p = 0.25 ) , EDSS ( absolute difference -0.01 , 95 % CI -0.35 to 0.35 ; p = 0.97 ) , MSFC components , grip strength , or fatigue . Conclusion : Supplementation with 20,000 IU vitamin D3 weekly did not result in beneficial effects on the measured multiple sclerosis-related outcomes . This study was not powered to address clinical outcomes , but none of the results were suggestive of an effect in this unselected population of fully ambulatory persons with multiple sclerosis There is an ongoing debate over the role of serum 25(OH ) vitamin D [ 25(OH)D ] levels in maintaining or improving physical performance and muscle strength . Much of the controversy is because of the variability between studies in participants ' characteristics , baseline serum 25(OH)D levels , and baseline physical functioning . The aim of this ancillary study conducted within a r and omized controlled clinical trial was to investigate whether supplementation with 400 or 2000 IU vitamin D3 daily for 6 months would improve measures of physical performance and muscle strength in a community-dwelling elderly population aged 65 to 95 years . Those with the slowest gait speed improved their ability to do chair-st and tests after vitamin D supplementation . This finding remained significant after controlling for potential confounding variables . There was also an inverse correlation between serum 25(OH)D levels and fat mass index ( FMI ) among women , suggesting that higher supplementation with vitamin D is needed as weight increases . The results of this study suggest that supplementation with vitamin D may be most beneficial in older population s who have low baseline physical functioning
Conclusion Although , serum 25(OH)D concentrations after supplementation reached sufficiency was observed , muscle strength did not significantly improve at this point of current meta- analysis .
Background The purpose of this systematic review and meta- analysis is to investigate the effects of vitamin D3 supplementation on skeletal muscle strength in athletes .
Vitamin D3 supplements or vitamin D3 fortified foods always have cl aims for bringing people health benefits including bone and muscle health .
An up-to- date rigorous systematic review and meta- analysis is important to better underst and the effect of vitamin D3 supplementation on muscle strength .