Properties and Benefits of Vitamin A or Retinol
Properties and Benefits of Vitamin A or Retinol: Discovered in the 1930s by the Swiss chemist Kerrer, vitamin A is a fat-soluble vitamin that is present both in food of animal origin and in plants in various active forms, including retinaldehyde, essential for sight, and retinoic acid, essential for growth from the embryonic phase. Retinol and retinoids, i.e. its derivatives, come from foods of animal origin, while carotenoids also known as provitamin A come from plant foods. Carotenoids are important mainly for their antioxidant action. A particularly useful carotenoid for slimming diets is lycopene, of which tomatoes are very rich: its antioxidant action protects cells from aging and degenerative damage produced by free radicals because it prevents the oxidation of LDL cholesterol, responsible for both the formation of atherosclerotic plaques and deposits of white fat on the abdomen. In the physiology of the body, vitamin A has many functions: it strengthens and maintains healthy skin, hair and mucous membranes, protects the lungs from infections and is a valuable healing aid in the treatment of acne and furunclesis: applied externally in the form of ointment, promotes the healing of skin ulcers. It also participates in the enzymatic processes necessary for the proper development of bones and the proper functioning of the ovarian and testicular system, and is essential both for the health and functioning of the retina, and during pregnancy, to ensure embryonic development and the normal process of growth of the fetus, regulating the differentiation of tissues.
Vitamin A or Retinol: Vitamin A, or retinol, is present mainly in foods of animal origin. It is found, in particular, in the liver, milk and its derivatives (butter and cheese) and eggs. Many foods of vegetable origin contain carotenoids, precursors of vitamin A: red, yellow and orange fruits and vegetables (apricots, carrots, watermelons, berries, tomatoes). Vitamin A is sensitive to heat: many of its characteristics are lost during the cooking process. It is therefore better to eat them raw or after a short cooking time.
Foods rich in vitamin A and retinoic acid
Foods rich in vitamin A and retinoic acid: Stocking up on vitamin A is generally not difficult, because it is present in many foods in cod liver oil, liver, egg yolk, butter and in many vegetables such as raw carrots, spinach, cabbage, broccoli, savoy cabbage, garlic, wheat germ oil, parsley, dandelion, watercress, pumpkin, fresh spinach, chicory, tomato, lettuce, and in general in all yellow orange vegetables. Among the fruits, they are a source of vitamin A melon, apricot, peach, orange and watermelon. However, it is not uncommon that in case of gastro-intestinal diseases or infections you may encounter a deficiency of this important vitamin.
The first symptom of vitamin A deficiency
The first symptom of vitamin A deficiency: One of the symptoms most often related to vitamin A deficiency is seen "on the skin": when it is insufficient, the skin appears dull, wrinkled and dry. Vitamin A is in fact necessary for the skin, because it influences the metabolism of the cells, regulating the permeability and elasticity of the cell membranes of the skin and mucous membranes and protecting them from the infiltration of harmful substances. Skin rich in vitamin A is visibly softer, smoother, younger and more elastic. Vitamin A has a very specific function in vision: to bind to a protein to make up rhodopsin, a photosensitive protein present in the rods, the retinal photoreceptors sensitive to light of low intensity. A lack of vitamin A causes a shortage of rhodopsin in the retinal rods and can therefore cause a visual disturbance quite common, the alteration of twilight vision: after sunset or in poor lighting conditions those suffering from this hypovitaminosis may have more difficulty than normal to drive, or to enter suddenly in a dark room, as happens, for example, passing from the atrium of a cinema to the screening room.