Vitamin D plays an essential role in the absorption of calcium and phosphorus by the body. It is essential for its proper functioning and is soluble in fats. Vitamin D behaves like a hormone and can be stored in fat as well as the liver, from which it can then released according to the needs of the body.
Besides its role in bone mineralization, vitamin D also helps stimulate innate immunity, improves muscle performance, reduces the risk of certain cancers and dementia.
About two thirds of vitamin D is made by the skin. The food we eat takes care of providing the rest. Vitamin D supplementation is recommended during periods of poor sunlight, especially in winter. Vitamin D comes in different forms, including vitamin D2 and D3.
Many people think that vitamin D2 is of plant origin and that vitamin D3 is of animal origin. However, plant vitamin D3 does exist. Certainly, vitamin D3 is present in oily fish or even egg yolks, but it is also found in lichen.
What are the differences between vitamin D2 and D3?
Vitamin D3 or cholecalciferol is a fat soluble vitamin. It is supplied exogenously through food and endogenously through exposure to the sun.
Vitamin D2 or ergocalciferol is present in small amounts in many foods such as grains and mushrooms.
Vitamins D2 and D3 are metabolized in the liver to calcifediol. The latter passes through the kidneys and leads to the release of calcitriol which is the active form of vitamin D. Less stable than vitamin D3, vitamin D2 is more sensitive to humidity and heat. In addition, vitamin D3 is thought to increase the level of calcitriol in the body more than vitamin D2. Doctors recommend supplementation with vitamin D3 because it is better absorbed by the body.
What are the benefits of vitamin D?
Vitamin D is known for its role in healthy bones and teeth by helping to regulate the absorption of phosphorus and calcium in the body. It facilitates their absorption and the fixation of these minerals on the bones and teeth. It helps build strong bones and prevents fractures and osteoporosis.
A sufficient amount of vitamin D also ensures the proper functioning of the neuromuscular and immune systems.
Vitamin D is used to prevent rickets, a growth disorder that is characterized by a defect in calcification of the skeleton.
Where can I find vitamin D?
Vitamin D is found in small amounts in food. Vitamin D2 is found in cereals and mushrooms while vitamin D3 is found in oily fish and some varieties of lichen.
Food does not fully cover vitamin D needs. It is therefore essential to be in the sun for about ten minutes each day. During winter, the wavelength of ultraviolet rays does not allow vitamin D to be absorbed through the skin. Vitamin D deficiency affects around 42% of the US population.
Vitamin D is fat soluble and stored by the body. There is thus a risk of overdose. In excess, vitamin D can be toxic. It is therefore important to respect the prescribed doses.
