Vitamin A is a key nutrient for maintaining eye health, preventing eye inflammation and reducing their risk of cataracts.At the same time, vitamin A helps boost immunity, it is a powerful antioxidant, prevents skin dryness, keeps skin bright, without wrinkles and other aging signs and is a key element in maintaining the health of hair, teeth and gums.
Vitamin A is usually found in animal products, in combination with lipids (eg: in dairy products and liver), but also in margarine. The precursors of vitamin A (carotenoids) are found in colored plants (fruits and vegetables yellow and red).
During high temperature cooking, or by exposing to light, a large amount of vitamin A is lost – this explain the low content of vitamin A found in dry fruits, compared with fresh fruits.
Also called retinol, vitamin A is involved in many body processes, thus affecting eyesight and also the health of skin and bones. It is indispensable for eye health, especially for seeing at night, it plays an important role in cell differentiation and in maintaining the normal structure of cells, so it is essential in repairing processes, for healing and cell regeneration.
Also, the vitamin A is responsible for your skin tone, the lack of this vitamin is being visible on the outside through dryness, scaling and increased risk of skin infections. In addition, the dryness of mucous membranes can cause weakness of the immune system.
Cracked lips, a sign of lack of vitamin A.
Many body deficiency symptoms of vitamins and minerals occur at skin level. Explanation? Vitamins plays an important role in the production of collagen, a protein present in connective tissue, and which our body generates it less and less as we grow older. Therefore, the lack of vitamins and minerals can cause brown spots, dry skin and wrinkles.
The deficiency of vitamin A occurs in a diet low in dairy and vegetable products or in malapsorbtion syndrome. This represent the main cause of blindness due to corneal damage in undeveloped countries in Africa, Middle East and Southeast Asia.
Among the manifestations of vitamin A deficiency are degenerative changes of eyes (xerophthalmia) and skin (peeling). It may also be affected the tracheobronchial epithelium and urinary tract, pancreatic ducts, uterus and salivary glands. A immunity deficiency might also occur.
The first sign of vitamin A deficiency is the loss of visual acuity in dim light.
The excess of vitamin A can be toxic, and the manifestations of this kind of intoxication are diverse:
- dry skin;
- bone demineralization;
- increased intracranial pressure with papillary edema;
- hepatic fibrosis with portal hypertension.
Pregnant women who take vitamin A in excess may have a fetus with congenital malformations (craniofacial, cardiac) or can suffer a miscarriage. High doses of synthetic derivatives of retinol are teratogenic.
The excess of carotene may cause a orange staining of skin that can be confused with jaundice.
All manifestations of vitamin A poisoning are reversible after ceasing the excessive intake.
The recommended daily dose:
- 800 μg for women, children over 10 years old and elderly people;
- 1000 μg for men, adolescents and pregnant women;
- 1300 μg during lactation;
The richest sources of vitamin A are:
- liver and organs in general;
- dairy products;
- egg yolk;
- green fruits and vegetables (broccoli, spinach);
- yellow fruits and vegetables (yellow melon, potatoes);
- orange fruit and vegetables (carrots);
- red fruit and vegetables (bell pepper, tomatoes)