Food

Vitamin A

A popular component of anti-aging creams and one of the usual reasons to buy fish oil – vitamin a

He received his letter designation for being the first open vitamin.

Back in 1913 it was described by two independent groups of scientists. Have this vitamin other names: TRANS-9,13-Dimethyl-7-(1,1,5-trimethylcyclohexen-5-yl-6)-nonatetraen-7,9,11,13-ol and more familiar to our ears – retinol.

How come?

In nature, in its pure form, this fat-soluble vitamin is not found. And in food a person can get it in two different ways. The most easiest of products of animal origin, where the retinol is contained in ready to assimilate form.

More complex – from plants, containing the red vegetable dyes are carotenoids that is converted in the body into vitamin A. My name they got the English name of carrot – carrot — which was first highlighted.

The most famous carotenoid supplying the body with the largest amount of vitamin a-beta — carotene-is converted into it as a result of cleavage in the liver. Carotenoids can be found not only in plants – they are in algae and even mushrooms.

Why need?

The most well-known role of vitamin A is to provide good vision. It helps to synthesize the retinal visual pigment rhodopsin, which helps to capture even the weakest light and is responsible for night vision.

Retinol is also involved in the secretion of lacrimal fluid, which protects the cornea from drying out. And carotenoids lutein and zeaxanthin reduce the risk of cataract and slow down the degeneration processes in the visual apparatus.

Retinol is involved in the immune system. It improves the work of factors of nonspecific protection-barrier functions of mucous membranes, for example, in the mouth or nose. In addition, vitamin a increases the activity of leukocytes-white blood cells that destroy foreign particles that have penetrated the body.

Both retinol and carotenoids are powerful antioxidants that can neutralize the most dangerous types of free radicals (aggressive fragments of molecules that destroy the body's cells).

This vitamin helps the healing processes of the skin and its natural renewal. It is used for the production of cosmetic and medicinal products, for example, acne and acne. Vitamin A is added to anti-aging cosmetics, as retinol stimulates the production of collagen, preserving the elasticity of the skin.

Include it in the suntan - sunburn skin retinol accelerates its regeneration.

Retinol is involved in the production of human sex hormones and is very important during fetal nutrition.

How much?

The daily dose of vitamin A for men is about 1000 mcg, for women – 800 mcg, and for newborns – about 400 mcg. Retinol is able to accumulate in the body, if it enters in excess.

However, from carotenoids coming from plant food, vitamin a the body receives less than from animal products. One microgram of retinol is obtained from 6 µg of beta-carotene or 12 µg of other carotenoids, such as lutein, lycopene or zeaxanthin.

The dose of vitamin A entering the body should be carefully monitored during pregnancy, since its overabundance can lead to disruption of fetal development and the appearance of various birth defects in the child. Therefore, the reception of multivitamin complexes while waiting for the baby should be under the strict control of the attending physician.

And if not?

Vitamin a deficiency disrupts almost all systems of the body, and primarily affects the appearance. The skin becomes drier and begins to peel off, wrinkles appear on the face and hands, and dandruff in the hair.

But the most well-known sign of retinol deficiency is" night blindness " that is, reduced vision at dusk or in low light conditions. This condition is especially dangerous for those who have to spend a lot of time behind the wheel.

Lack of retinol causes other symptoms related to vision. Due to the deterioration of the formation of lacrimal fluid there is a feeling of "sand" in the eyes, redness and itching of the eyelids. This is the so-called dry eye syndrome.

Men lack of this vitamin can be noticed in the form of weakening of an erection and premature ejaculation. Frequent respiratory diseases and a serious decline in working capacity are also signs of a deficiency in vitamin A.

What interferes with absorption?

Since vitamin a is fat-soluble, the insufficient amount of fat in the diet, for example, with a strict unbalanced diet, seriously impairs its absorption by the body.

Those who are engaged in weight loss with the help of dietary supplements should carefully read their composition. If they contain mineral oils used as laxatives – vaseline or castor-they can dissolve vitamin a and remove it from the body.

Vitamin A is poorly absorbed in those who abuse alcohol and smoke – due to a violation of the liver, contributing to the absorption and storage of retinol.

It worsens the absorption of vitamin A and deficiency of its" partner " – vitamin E-and zinc.

What to eat?

Most retinol in fish oil and beef liver. It is enough in dairy products-milk, cream, butter and cheese, as well as chicken eggs.

Almost all bright yellow and red vegetables and fruits, as well as dark green leafy crops like spinach, broccoli or green onions are rich in carotenoids. There are carotenoids in the legumes.

Together with fats, beta-carotene is absorbed 30 percent better. But only if enters the body on an empty stomach, so it is not a reason to consume excess fat. For the normal absorption of beta-carotene is enough and those fats that a person receives during the day with food.

Most important

Vitamin A is essential for good vision, immunity and beauty of the skin and hair. It can be obtained in two ways-from animal products and plant foods, in which it is contained in the form of Pro-vitamin A.

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