Essential to the body, vitamin A is particularly important to ensure the good health of your eyes. So, where can you find this vitamin in your daily foods? What are the symptoms of a lack of vitamin A? And how to avoid a deficiency?

Vitamin A: what is it?

Definition.

Vitamin A is a fat-soluble vitamin, like vitamins D, E and K. That is to say, it is soluble in fatty substances. It exists in the forms of retinol and carotenoids: – Vitamin A or retinol: this form of vitamin A is found exclusively in foods of animal origin. Its name comes from the fact that vitamin A has beneficial actions on the retina of the eye. – Provitamin A: our liver has the capacity to synthesize vitamin A from carotenoids, a pigment present in plants. For example, beta-carotene is said to be a precursor of vitamin A.

Roles of vitamin A.

Vitamin A plays several important roles within the body, particularly in terms of vision.

• Stimulation of visual functions: it reduces the risk of cataracts and macular degeneration. This disease is responsible for the progressive loss of vision. It also allows the eyes to adapt to darkness by transmitting nerve impulses through the optic nerve to the brain. In addition, retinol is essential for the synthesis of visual pigments which allow us to distinguish shapes and colors.
• Immune system: vitamin A strengthens the immune system and provides better resistance to infections by stimulating the proliferation of white blood cells and the production of antibodies.
• Protection and integrity of tissues: it helps consolidate bones. It contributes to the good condition of the skin and mucous membranes as well as the growth and renewal of cells.

Like many vitamins, beta-carotene (precursor of vitamin A) has an antioxidant action. In fact, it will limit cellular aging processes by fighting against free radicals.

Our daily vitamin A needs.

According to ANSES, the daily needs of men and women for vitamin A differ. Women: 650 micrograms of RE/day Men: 750 micrograms of RE/day The retinol equivalent (RE) is the international unit of vitamin A. This allows the vitamin activity of the different precursors of this vitamin A to be compared. For example, you get 1g of retinol from 6g of beta-carotene.

Did you know ?

During pregnancy, excess vitamin A can cause birth defects. Pregnant women are advised to monitor their consumption of foods rich in direct vitamin A (such as liver or offal) but to favor fruits and vegetables because this source of provitamin A is safe and will only be converted into vitamin A. if needed. It is recommended that 60% of daily vitamin intake comes from fruits and vegetables.

What foods are rich in vitamin A?

Retinol is a form of vitamin A that is found exclusively in foods of animal source while provitamin A is synthesized from beta-carotene, a pigment present only in plants.

Vitamin A deficiency.

An unbalanced diet can be enough to cause a vitamin A deficiency. In addition to reducing your visual acuity and your night vision, an insufficient intake can result in dry skin, hair loss, and nails that become more brittle. . In the long term, a significant deficiency of vitamin A can lead to blindness. However, it should be noted that vitamin A deficiency is rare in developed countries.

The consequences of a surplus of vitamin A: hypervitaminosis.

An excess of retinol can be the consequence of overconsumption of foods rich in vitamin A or food supplements. An overdose of vitamin A can lead to headaches, nausea and joint pain. However, there is no need to panic. Finding yourself in a vitamin A surplus situation is extremely rare.

In summary.

Vitamin A is a fat-soluble vitamin that exists in 2 forms: retinol and provitamin A. Provitamin A comes mainly from plant sources while retinol is only present in foods from animal sources. Deficiencies are rare. If they were to nevertheless appear, they would manifest themselves in dryness of the skin, hair loss, brittle nails but also, more seriously, loss of vision.04