The research was led by Research Fellow Dr Pang Yao and Robert Clarke, Professor of Epidemiology and Public Health Medicine, at NDPH. The researchers combined findings from 11 observational studies of vitamin D blood levels and the associated risk of fracture with more than 39,000 participants, 6 trials of combined vitamin D and calcium treatment with more than 49,000 participants, and 11 trials of vitamin D supplements alone with 34,000 participants. The research has been published in JAMA Network Open.
The observational studies showed that low blood levels of vitamin D are associated with higher risks of fracture, but the trial results have been inconclusive. The trials of vitamin D plus calcium showed a small reduction in the risk of fractures. In people over the age of 80 years, and those living in institutions however, the effects were greater, with the risk of hip fracture lowered by almost one-third. While the trials of vitamin D alone did not show a reduction in the risk of fracture, these trials included some large studies of very high annual doses of vitamin D which increased the risk of fracture, and few of the trials tested doses of vitamin D high enough to raise the blood levels of vitamin D sufficiently to reduce the fracture risk.
Read more (University of Oxford)