The effects of vitamin D on skeletal muscle strength, muscle mass and muscle power: a systematic review and meta-analysis of randomized controlled trials.
J Clin Endocrinol Metab. 2014 Jul 17:jc20141742
Beaudart C1, Buckinx F, Rabenda V, Gillain S, Cavalier E, Slomian J, Petermans J, Reginster JY, Bruyère O.
1Department of Public Health, Epidemiology and Health Economics, University of Liège, Liège, Belgium;
Context There is growing evidence that vitamin D plays a role on several tissues including skeletal muscle.
Objective To summarize with a meta-analyse the effects of vitamin D supplementation on muscle function.
Data sources A systematic research of randomized controlled trials, performed between 1966 and January 2014 has been conducted on Medline, Cochrane Database of Systematics Reviews, Cochrane Central Register of Controlled and completed by a manual review of the literature and congressional abstracts.
Study selection All forms and doses of vitamin D supplementation, with or without calcium supplementation, compared with placebo or control were included. Out of the 225 potentially relevant articles, 30 randomized controlled trials involving 5615 individuals (mean age: 61.1 years) met the inclusion criteria. Data extraction Data were extracted by two independent reviewers.
Data synthesis Results revealed a small but significant positive effect of vitamin D supplementation on global muscle strength with a standardized mean difference (SMD) of 0.17 (p=0.02). No significant effect was found on muscle mass (SMD 0.058; p=0.52) or muscle power (SMD 0.057; p=0.657).
Results on muscle strength were significantly more important with people who presented a 25-hydroxyvitamin D level <30 nmol/L. Supplementation seems also more effective on people aged 65 years or older compared to younger subjects (SMD 0.25; 95% CI 0.01 to 0.48 versus SMD 0.03; 95% CI -0.08 to 0.14).
Conclusions Vitamin D supplementation has a small positive impact on muscle strength but additional studies are needed to define optimal treatment modalities, including dose, mode of administration and duration.