How useful vitamin A

Vitamin A is important for good vision , especially for the ability to see well in low light conditions. Also, without enough vitamin A in the body impossible normal bone growth , normal sexual development of the individual , the health of the skin and mucous membranes bodies. Vitamin A, as well as vitamin E, belongs to antioxidants and protects the cells of the body against free radicals , preventing cell mutation and tumor formation.

Our body gets vitamin A in two ways. In the first case , this vitamin comes to us in products of animal origin , which contain the active form of vitamin A - retinol and retinal . These active form without further chemical reactions involved in direct metabolism. In the second case, vitamin A is synthesized in the body of the carotenoids , which are found in many fruits and vegetables yellow, orange or dark green in color . The most famous of the carotenoid is β- carotene. The amount of vitamin A, entering the human body through the consumption of fruits and vegetables, often measured in retinol equivalents RE. RE unit corresponds to 1 mcg of retinol or 6 mg β- carotene , which is also equivalent to 3.3 international units (IE) of vitamin A.

Vitamin A is a fat-soluble vitamins relates to and can accumulate in the body prozapas . Most of the vitamin A obtained from food is stored in special cells of the liver. If somewhere in the body there is a need for vitamin A , liver cells release the amount required , and the bloodstream , it is transferred to the right place.

Daily requirement of vitamin A for adult males is 1 mg for women - 0.8 mg . Good sources of vitamin A are the following products in the 50-200 g which contains not less than 0.15 mg vitamin A or β- carotene : sweet potatoes ( yams ) , carrots, pumpkin , spinach , red peppers, apricots , tomatoes , cantaloupe, mangoes, eggs, liver (beef, pork, chicken, turkey ).

Most often, vitamin deficiency and hypovitaminosis A occurs in children and pregnant women. Besides vitamin A deficiency is common in people who abuse alcohol , as well as in patients with the problems of fat resorption.
One of the known symptoms of vitamin A deficiency in the body is xerophthalmia - an eye disease that causes a clouding of the retina. As a consequence there may be a night blindness, retinal ulceration , which can lead to total blindness . Other symptoms may include growth retardation in children , poor wound healing , disease, skin and mucous membranes.