The benefits and harms of vitamin A says Oleg Vladimirov.
About vitamins humanity learned relatively recently - the first one was opened in 1920, and was it just vitamin A.
Like other vitamins, it has many useful properties: it is an antioxidant, participates in the redox processes of the body, in the regulation of protein synthesis and normalization of metabolism. It is necessary for the formation of bones and teeth, for the growth of new cells, slows down the aging process. It is very important for vision, healthy skin and hair, as well as for the functioning of the immune system.
Sources of vitamin A are:
butter egg yolks
whole fresh (preferably fresh) milk
Contrary to popular belief beef и crops contain vitamin A in very small quantities, besides, it is poorly absorbed from them, even artificial fortification does not help.
Plant products contain orange-red pigments - provitamins A, which belong to the group of carotenoids and turn into vitamin A in the walls of the small intestine. WITHcarotene was howling name because of his carrot-colored, it is a kind of nature clue, because it contains not only a carrot but also in other fruits and vegetables red-orange color.
There is a pharmacy and a form of vitamin A (retinol).
Vitamin A - is a fat-soluble, which means that none of the forms without the presence of not digestible fats in the diet. That is, to assimilate carotene, add a little sour cream to the carrot salad, and 2-3 tbsp. To a glass of carrot juice. tablespoons of milk with an average percentage of fat (3,2-3,5%) or a few drops of any vegetable oil. A classic orange-based salad with the addition of fennel, chicory or other lettuce leaves can also be a source of carotene, but most importantly - the same vegetable oil. For those who are not on a diet, I can also offer strawberries with cream, only the cream must be natural, otherwise the carotene will not be absorbed.
Remember that the amount of vitamin A you want to control: excessive intake into the body can be life-threatening. For example, living in the Arctic peoples do not eat polar bear liver - even in a small piece of it contains a lethal dose for a human vitamin A. First, researchers did not know the North, which caused the death of several members of the polar expeditions.