Enough data to draw conclusions about vitamin D and bone health

The experts’ comments in the news article by Torjesen about our systematic review on the effects of vitamin D supplementation are incorrect or mistargeted.12

Clarke’s comments are wrong. He says that the trials in our meta-analysis had too few participants, used an insufficient dose of vitamin D, and had an insufficient duration of treatment to warrant changing health recommendations, and he suggests waiting for more trial results. But ample data exist to permit reliable conclusions. The trials on falls and fracture in our review comprised >34 000 participants, 3534 fractures, 870 hip fractures, and 14 139 falls. Almost all recent trials used >800 IU/day vitamin D, and 17 trials of falls and fractures lasted >12 months. Ongoing vitamin D trials are not targeting populations most likely to benefit from supplementation (such as those with serum 25 hydroxyvitamin D <25 nmol/L).3 Trial sequential analyses show that there is reliable evidence that vitamin D supplementation does not have clinically relevant beneficial effects on falls, fracture, or bone density and that future similar trials are unlikely to change these conclusions. So there is no reason to defer drawing conclusions about vitamin D supplementation.

Martineau says that supplementing the entire UK population with vitamin D will prevent the most extreme complications of rickets. This comment is not relevant to our review of vitamin D supplementation of adults for musculoskeletal health. As Torjesen noted, we specifically stated that people at high risk of rickets and osteomalacia should receive vitamin D supplementation. Supplementing adult populations, however, who are recommended vitamin D to maintain or improve musculoskeletal health in many current clinical guidelines, will not prevent rickets but will mean that vast numbers of people take vitamin D supplements for no benefit.