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

Vitamin A: What is it?

Definition.

Vitamin A is a fat-soluble vitamin, like vitamins D, E, and K. That is, 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 effects on the retina of the eye. – Provitamin A: our liver has the ability 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 in the body, particularly in vision.

• Stimulates 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 that 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.
• Tissue protection and integrity: It helps strengthen bones. It contributes to the good condition of the skin and mucous membranes as well as to cell growth and renewal.

Like many vitamins, beta-carotene (a precursor to vitamin A) has antioxidant properties. It limits cellular aging processes by fighting free radicals.

Our daily vitamin A requirements.

According to ANSES, men and women have different daily vitamin A requirements. 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 us to compare the vitamin activity of different precursors of this vitamin A. 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 intake 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 when needed. It is recommended that 60% of daily vitamin A intake come from fruits and vegetables.

What foods are rich in vitamin A?

Retinol is a form of vitamin A found exclusively in animal foods, while provitamin A is synthesized from beta-carotene, a pigment found 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 night vision, insufficient intake can manifest itself through dry skin, hair loss, and brittle nails. In the long term, a significant vitamin A deficiency can lead to blindness. However, it should be noted that vitamin A deficiencies are rare in developed countries.

The consequences of excess vitamin A: hypervitaminosis.

Excess retinol can be the result of overconsumption of vitamin A-rich foods or supplements. A vitamin A overdose can lead to headaches, nausea, and joint pain. However, there's 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 two forms: retinol and provitamin A. Provitamin A comes primarily from plant sources, while retinol is found only in animal-based foods. Deficiencies are rare. If they do occur, they can manifest as dry skin, hair loss, brittle nails, and, more seriously, vision loss.04