Vitamin D plays a vital role for our health.
Discovered in 1922 by the American biochemist Elmer Mc Collum, vitamin D can be synthesized by the body thanks to the ultraviolet rays of the sun (UVB).
Why is vitamin D essential?
- It is essential for fixing calcium in the body.
- It regulates blood calcium levels by improving intestinal absorption and reducing its elimination through the urine.
- It contributes to healthy bones (helping them to grow) and teeth.
- It maintains the function of the immune, cardiovascular and neuronal systems.
- It plays a role in the process of cell division.
Recommended vitamin D intake is 5 μg for both men and women.
The populations of the less sunny countries, but also certain categories of population which go out rarely (sick, elderly …) can suffer from deficiency due to a lack of exposure to the UV of the sun.
In addition, the body’s ability to absorb and synthesize vitamin D decreases with age.
According to a US study that has monitored more than 13,000 patients over ten years, a vitamin D deficiency would be associated with an excess of mortality of 26%, from all causes.
It causes muscle pain, increases the risk of fracture (osteoporosis) and is associated with a higher risk of cardiovascular disease and cancer. In general, it seems that vitamin D is correlated with many diseases even if no study can prove for the moment.
In children, vitamin D deficiency causes rickets. It is characterized by stunted growth, motor development and poor bone formation. This disease corresponds to osteomalacia in adults. It is manifested by bone demineralization leading to diarrhea and nervousness.
Where to find Vitamin D?
The body has the ability to directly synthesize vitamin D through the skin, under the effect of UV rays of the sun. It is recommended that the hands, forearms and face be exposed for at least 10 to 15 minutes a day and on average 2 to 3 times a week. A sun protection index 15 minimum is strongly recommended for prolonged exposures, beyond 15 minutes. These indications are an average and can vary from one individual to another, depending on the type of skin, the intensity of light rays.
Diet can also bring vitamin D. Cod liver oil, salmon, tuna, herring are rich in vitamin D. Egg yolk, butter and fat cheese also contain it. You also find a lot of vitamin D in fortified milk. Vitamin D can be stored in reserve fats and liver for future use by the body.
How to detect a deficiency?
A blood test will indicate the level of vitamin D. Your doctor will then tell you if it is necessary to take supplements that he will prescribe in this case.