Effects of vitamin D supplementation on strength, physical performance, and falls in older persons: a systematic review.

OBJECTIVES: identify, appraise, and synthesize data from randomized, controlled trials of vitamin D supplementation in older people.
DESIGN: A systematic review of trials identified from searches of databases, reference lists, review articles, and recent conference proceedings.
SETTING: Most studies performed in ambulatory setting. PARTICIPANTS: Older people (mean age=60).
INTERVENTIONS: Vitamin D or vitamin D metabolites. MEASUREMENTS: Strength, physical performance, or falls.
RESULTS: Thirteen trials involving 2,496 patients met this study's inclusion criteria. Most of the trials were small and had methodological problems. In 10 trials, there was no evidence that vitamin D or vitamin D metabolites had an effect on falls or physical function, but three trials showed a positive effect of vitamin D in combination with calcium. When available data from the four highest quality trials were pooled (n=1,317), there continued to be no evidence that vitamin D reduced the risk of falling (relative risk= 0.99, 95% confidence interval=0.89-1.11), although a single trial of vitamin D and calcium showed a positive effect.
CONCLUSION: Although there is insufficient evidence that vitamin D supplementation alone improves physical performance in older people, some data suggest a benefit from vitamin D combined with calcium supplementation, but this requires confirmation in large, well-designed trials.