Two recent clinical trials show that the popular belief that vitamin D supplementation prevents bone fractures and prolongs life based on vitamin D’s biochemical mechanisms is not clinically supported.
The nutritional supplement market is trying to meet the need of our time: people want to take care of their health, even if they are fine. They want to maximize their well-being, reduce the risk of disease, sometimes free themselves from the authority of medicine, so there are many reasons why nutritional supplements are an attractive technical solution. Indeed, medical knowledge is always situated: it is usually expressed only for a specific group of patients (problem of external validity). which multicenter trials are trying to address) and for certain endpoints (a marker, a etc.). There is no magic bullet for new health goals for a subset of the population.
The dietary supplement market is rarely weighed down by these considerations. Mechanistic reasoning based on biochemical knowledge of our body or isolated clinical studies without statistical power is sufficient for this. Indeed, this can lead supplement sellers to endorse pseudo-efficacy by using complex scientific language or by claiming that efficacy is clinically proven in flimsy studies they themselves funded. Since then, we find ourselves in a cacophony of products to boast about yours silence your indigestion or make you . It’s a bit like whose merits are praised for immunity, fractures, mortality, etc. Two clinical trials are coming of these shared beliefs.
Strong clinical trials
These two trials lasted a long time: the first five years, the second five years and three months.
is double blind vs and trials to assess the effect of 60,000 IU of vitamin D per month on mortality in Australians aged over 60 years, not studied for vitamin D. As a result, vitamin D intake had no significant effect of mortality.
is a randomized controlled trial (with randomized ) triple-blind versus placebo. The main trial (VITAL) was designed to determine the effect of use on one side and vitamin D on the other from and . The additional study discussed focused on self-reported fracture risk. In more than 25,000 US patients who were not screened for vitamin D deficiency, there was no reduction in fracture risk with vitamin D.
What should we conclude from this?
Vitamin D intake does not appear to affect mortality or fracture risk in people over 60 years of age. lack of It is then advisable to be wary of taking supplements that do not have a proven benefit, as the risks can sometimes be poorly assessed, as suggested by . Obviously, these studies do not say anything about the effectiveness of vitamin D in other indications and in other types of patients.