Table 1: Summary of RCT and meta-analysis regarding effects of vitamin D on muscle function and falls.

Type of studyAuthorNumber of subjectsType of subjectsMean age (years)InterventionDurationResults

RCT Kenny et al. (2003) [48]65Healthy men761,000 IU/d vitamin D versus placebo6 monthsNo increase in muscle strength or improvement in physical performance.

RCTSongpatanasilp et al. (2009) [11]72Postmenopausal females70Ca 1500 mg/d + alfacalcidol 0.5 ug/d versus Ca 1500 mg/d12 weeksImprovement in muscular strength.

RCT Lips et al. (2010) [49]226Elderly males and females with vitamin D <50 nmol/L778400 IU/week vitamin D versus placebo16 weeksImprovement of balance in a subgroup with severe balance impairment at baseline.

RCTWard et al. (2010) [46]69Postmenarchal females (12 to 14 years old) with vitamin D <25 nmol/L134 doses of 150,000 IU vitamin D every 3 months versus placebo12 monthsIncrease in jump velocity in girls with low vitamin D levels.
No improvement in strength in others.

RCTGupta et al. (2010) [44]40Healthy males and females3160,000 IU/week for 8 weeks followed by 60,000 IU/month for 4 months vitamin D + 1000 mg Ca/d versus placebo6 monthsEnhanced skeletal muscle strength and physical performance.

RCTZhu et al. (2010) [45]300Elderly females with vitamin D <60 nmol/L771,000 IU/d vitamin D + Ca 1000 mg/d versus Ca 1000 mg/d + placebo 12 monthsEnhanced skeletal muscle strength and physical performance in patient with the lowest vitamin D level.

RCTTaskapan et al. (2011) [39]25 (CKD stages 3-4)
47 (PD)
CKD and PD with vitamin D <50 nmol/LNA50000 IU/week vitamin D 4 to 8 weeksImprovement in physical performance tests.

UCT Schacht and Ringe (2012) [56]2100Males and postmenopausal females 751 mcg/d calciferol6 monthsImproved physical performance.

RCTGlendenning et al. (2012) [52]690Elderly females (age >70)77150,000 IU/every 3 months vitamin D versus placebo 9 monthsNo differences in falls and physical performance between the groups.

RCTGoswami et al. (2012) [53]173Healthy females22 60,000 IU/week every 8 weeks then 60, 000 IU/fortnight + Ca 500 mg/d versus 60,000 IU/week every 8 weeks then 60, 000 IU/fortnight + placebo versus Ca 500 mg/d + placebo versus placebo 6 monthsNo differences in muscle strength between the groups.

RCT Ceglia and Harris (2013) [21, 27]21Females with limited mobility784000 IU/d vitamin D4 months Increase of intramyonuclear VDR concentration. Increase in muscle fibers.

RCTWyon et al. (2014) [47]24Elite ballet dancers282000 IU/d vitamin D versus placebo4 monthsIncreased muscle performance and less injury.

Meta Muir and Montero-Odasso (2011) [54] 2268 (13 RCTs)Elderly males and females (age >65)78Vitamin D supplementationBeneficial effects on strength and balance.

MetaStockton et al. (2011) [55] 5072 (17 RCTs)Males and females of all agesNAVitamin D supplementationIncrease in muscle strength in adults with baseline vitamin D <25 nmol/L.

RCTBischoff et al. (2003) [63]122Elderly females85Ca 1200 mg and 800 IU/d vitamin D versus Ca 1200 mg/d12 weeksReduced risk of fall.

RCTPfeifer et al. (2009) [62]242Community-dwelling elderly males and females77 800 IU/d vitamin D + Ca 1000 mg/d versus Ca 1000 mg/d 12 monthsReduced number of falls and improvement in muscle function.

Meta Gillespie (2003) 461 (3 RCTs)Elderly males and femalesNAVitamin D supplementationNo reduction in the risk of fall.

Meta Bischoff-Ferrari et al. (2004) [66]10001 (10 RCTs with sensitivity analysis)
1237 (5 RCTs without sensitivity analysis)
Elderly males and females, age >6570Vitamin D supplementationReduced risk of fall.

Meta Michael et al. [64] (2010) 5809 (9 RCTs)Elderly males and femalesNAVitamin D supplementationReduced risk of fall.

MetaMurad et al. (2011) [65]45782 (26 RCTs)Males and females (all ages)NAVitamin D + Ca supplementationReduced risk of fall.

RCT: randomized control trial, UCT: uncontrolled trial,Meta: meta-analysis, NA: nonavailable, CKD: chronic kidney disease, PD: peritoneal dialysis, VDR: vitamin D receptor, and Ca: calcium.