Clinical review: The effect of vitamin D on falls: a systematic review and meta-analysis.

Context: Vitamin D affects bone and muscle health and likely reduces the risk of falls in the elderly.

Objective: The aim of this systematic review is to summarize the existing evidence on vitamin D use and the risk of falls.

Data Sources: We searched electronic databases from inception through August 2010.

Study Selection: Eligible studies were randomized controlled trials in which the intervention was vitamin D and the incidence of falls was reported.

Data Extraction: Reviewers working in duplicate and independently extracted study characteristics, quality, and outcomes data.

Data Synthesis: Odds ratio and associated 95% confidence interval were estimated from each study and pooled using the random effects model.

Results: We found 26 eligible trials of moderate quality that enrolled 45,782 participants, the majority of which were elderly and female. Vitamin D use was associated with statistically significant reduction in the risk of falls (odds ratio for suffering at least one fall, 0.86; 95% confidence interval, 0.77-0.96). This effect was more prominent in patients who were vitamin D deficient at baseline and in studies in which calcium was coadministered with vitamin D. The quality of evidence was low to moderate because of heterogeneity and publication bias.

Conclusions: Vitamin D combined with calcium reduces the risk of falls. The reduction in studies without calcium coadministration did not reach statistical significance. The majority of the evidence is derived from trials enrolling elderly women.