There is little reason to prescribe vitamin D supplements to healthy adults to reduce the risk of diseases or fractures, according to new research in the Lancet.
A study found no significant reduction in risk in any area after more than 100 trials ,and future studies were unlikely to change the figures, researchers said.
At-risk groups, including babies, pregnant women and elderly people, are still advised to take supplements.
The research team, from the University of Auckland in New Zealand, had previously carried out a meta-analysis that showed no major effect of vitamin D supplementation on bone mineral density.
In this study, they looked at existing randomised controlled trials of vitamin D supplements, with or without calcium.
They found that vitamin D supplementation does not change the relative risk of heart disease, stroke or cerebrovascular disease, cancer and fractures by a noticeable amount, equivalent to 15%.
Vitamin D supplements did not reduce hip fracture risk by more than 15% in hospital patients and, when given with calcium, did not lessen the risk in healthy individuals either.
The study said there was also "uncertainty as to whether vitamin D with or without calcium reduces the risk of death".
