Vitamin D prophylaxis v a control condition (eg, calcium or placebo) in older people*

Outcome (3 mo to 3 y)Number of RCTs (n)Weighted event ratesRRR (95% CI)NNT (CI)
Vitamin DControl
*RCTs  =  randomised controlled trials. Other abbreviations defined in glossary; weighted event rates, RRR, NNT, and CI calculated from data in article using a random-effects model.
Participants who had ⩾1 fall5 (1237)30%37%19% (6 to 31)15 (9 to 52)