The first vitamin discovered, the first letter of the alphabet. Two researchers discovered this growth factor in milk in 1913, and more than 30 years later, it was successfully synthesized.
In its fully developed, directly assimilated, and usable form (retinol), it is only provided by animal sources. But precursors are found in plants, particularly beta-carotene, which is easily assimilated by the body. And here, it’s hard to go wrong: the more yellow or orange the vegetable or fruit, the more it contains.
What are the main functions of vitamin A?
- Crucial for vision (at the level of the retina); vitamin A deficiency is one of the leading causes of blindness in developing countries
- For cell renewal and healing of the skin and mucous membranes (its derivatives are used in many skin pathologies due to dysfunction, including acne, psoriasis); it is essential for the proper development of the embryo, and its deficiencies lead to fetal malformations.
- In immunity, by helping to produce antibodies; for example, in disadvantaged countries, its deficiencies are found to be associated with excess mortality from measles.
- It is one of the vitamins that act against free radicals, thus influencing the mechanisms of aging and tissue degeneration.
What degrades vitamin A?
It is not very degraded during cooking, but on the other hand, it is sensitive to light and air (it oxidizes).
What are the first symptoms of vitamin A deficiency?
- Night vision problems, dry and cloudy cornea
- Growth disorders
- Greater susceptibility to infections
- Tooth alterations
- Intestinal disorders
Beware of overdosing on vitamin A… But above all, don’t go overboard! It is fat-soluble and will therefore be stored in the body (the liver in particular) rather than eliminated.
What are the risks of prolonged high doses of vitamin A?
- Vision problems: double vision
- Liver enlargement with dysfunction
- Headaches, vomiting, which may indicate excess intracranial pressure, through a complex mechanism
- Paradoxically, a drying out of the skin is linked to excessive renewal
- Joint and bone pain
There is no risk of overdose with plant sources, as the body will transform them into an active form according to its needs.
What foods are rich in vitamin A?
The main sources of 100 grams of food are:
- All livers: This is the storage organ for vitamin A. Its consumption is very useful, but should remain infrequent, for example, one to three times per month; otherwise, you will exceed the ceiling of the recommended daily intake (RDI).
- The famous cod liver oil: cod liver toast as a starter is better
- Carrots: 200% of the RDA
- Sweet potatoes: 150% of the RDA
- Chard, pumpkins: 100% of the RDA
- Endives, eel, apricots: 90% of the RDA
- Cantal, spinach: 70% of the RDA
- Spinach, fennel, escarole, sorrel, prunes, nectarines; 60% of the RI
- Conger eel, Gruyère, Holland cheese, mango, persimmon, peppers, broccoli: approximately 50% of the RDA
- Fermented cheeses, eggs, tomatoes, asparagus, curly lettuce, tomatoes, peaches: around 30% of the RI
- Lots of aromatic herbs, more anecdotal for the importance of the contributions