Vitamin D is an important vitamin for the body. It is necessary for bone mineralization and is also involved in immunity. Vitamin D acts as a hormone, which explains why it has general health effects. It is both anti-infective and anti-inflammatory… It is also involved in blood pressure regulation.
Vitamin D is produced by the skin when exposed to UV rays. Most of our vitamin D intake – more than 80% – comes from the sun. Therefore, sunlight is very important to meet our needs.
In our latitudes You can get enough vitamin D by exposing your forearms, face and neck without sunscreen for about a quarter of an hour between April and October., but in autumn and winter, when there is a lack of sun, it is much more difficult and especially UVB.
It is estimated that approximately 40% of the population is vitamin D deficient, that is, their blood concentration is below 20 nanograms per milliliter, especially in late winter. 6% would definitely be lacking.
Foods rich in vitamin D
Vitamin D is also found in food, fatty fish, dairy products, egg yolk, certain mushrooms… However, food alone corrects only a very small part of the problem. Its contribution is limited and is only 10-20% of our needs. There is cod liver oil, which is rich in vitamin D. Also, our ancestors used to give it to children to prevent rickets. However, not everyone appreciates its taste.
All this explains why supplements are often prescribed in winter, in the absence of official recommendations. This is even more true for the elderly, because even when they are in the sun, they synthesize vitamin D less. at the level of the skin,” Cédric Annweiler, an geriatrician at Angers CHU, explained to me.
Who needs to top up?
To a recent reviewThe National Public Health Council does not recommend supplemental vitamin D for adults. He believes that there are no reliable scientific studies that support its benefits in healthy people.
It is true that studies have shown that vitamin D deficiency is associated with a higher risk of infections, cancer and cardiovascular problems. But beware of the link, correlation does not mean causation, and nothing serious has yet been proven about the supposed protective role of vitamin D supplementation against the onset of these diseases.
Also, we cannot claim that supplements are completely risk-free.. Therefore, it is not advisable to use vitamin D for self-medication. Public health physician and epidemiologist Agathe Billette de Villemeur points out that “today, the benefit of dietary supplements is only proven in cases of osteomalacia – when your bones are soft – related to the actual deficiency, which is less than 10 nanograms per milliliter in the blood.
For people at particular risk of vitamin D deficiency, such as the elderly, institutionalized people, obese people, or people with highly pigmented skin…you can ask your doctor about supplementation on a case-by-case basis.. However, there is insufficient scientific evidence to recommend systematic supplementation.