What you need to know about vitamin d


Discovered in the early 20th century following epidemics of rickets, vitamin D (also known as calciferol) is vital for healthy bones and teeth. It plays an essential role in the metabolism of calcium in the body. It is also suspected of influencing other phenomena such as cell differentiation, DNA repair, and insulin secretion.

vitamin d benefits

Sources of vitamin D

Few common foods provide appreciable amounts of vitamin D. These include some fish (salmon, swordfish, eel, bluefin tuna, trout, herring, halibut), egg yolk, and to a lesser extent beef liver and fortified milk.

Fortunately, the body is able to synthesize it itself: under the effect of the sun's ultraviolet rays, it produces a derivative called cholecalciferol, which takes its active form after passing through the kidney. A too weak exposure to the sun, as it can be the case in winter or in the event of intense pollution, can thus lead to a deficiency in vitamin D. A dietary intake of about 15 µg of vitamin D per day is recommended1 for people between 1 and 70 years of age and 20 µg for older people.

Vitamin D deficiency

Vitamin D is an exception among nutrients and vitamins because it can accumulate in fats and in the liver where it is stored. At any time, it can be put back into circulation and used when needed. This means that it is possible, in case of deficiency, to supplement with a weekly or even monthly dose. Some studies have even shown that annual doses can be taken without adverse effects.

In children, vitamin D deficiency leads to rickets, which is characterized by stunted growth and motor development, poor bone formation, and sleep disturbances. In adults, this corresponds to osteomalacia, a disease that manifests itself by bone demineralization and great nervousness.

Other Supposed Virtues of Vitamin D

In recent years, vitamin D has raised high hopes for preventing the most common diseases, such as cancer and cardiovascular disease. Despite the thousands of studies that have been done on the subject, only modest effects have been demonstrated. On the other hand, some of them have demonstrated the effectiveness of vitamin D consumption in cases of psoriasis, osteoporosis, epilepsy, and also in the prevention of dental caries.