Vitamin D and calcium supplements are widely used for the prevention of bone fractures in older adults, but a large analysis confirms earlier reports they do not work.

Chinese researchers pooled data from 33 randomized, placebo-controlled trials with more than 51,000 participants to look for an association between taking the supplements and a lowered risk of fracture. The analysis, in JAMA, found none.

Some of the studies looked at calcium and vitamin D separately, others with the two supplements combined. Follow-ups varied from three months to as long as seven years.

Over all, the researchers found no association of vitamin D or calcium supplements, or both, with the frequency of hip, spine or total fractures. Nor was there any association of fracture with baseline vitamin D blood levels or with the dose of the supplements.