Vitamin A has many important functions in the body - it is essential in the process of vision, strengthens the immune system and can prevent the development of cancer. In addition, vitamin A improves the appearance of the skin, thanks to which it has been used in cosmetics, and the vitamin A ointment is a remedy for many skin problems. However, pregnant women should be careful with its dosage. What other properties does vitamin A have? What are the symptoms of its deficiency? In what products can it be found?

Vitamin Ais a term that refers to several substances - retinol and its derivatives (called retinoids) as well as beta-carotene and some other carotenoids. Vitamin A, along with vitamin D, vitamin E and vitamin K, belongs to the group of fat-soluble vitamins - it is stored in adipose tissue and in the liver. Thanks to this, it is more difficult to find a shortage of it, but on the other hand, its excess can be harmful. This is especially true for pregnant women.

Vitamin A occurs as retinol in animal products and in the form of provitamin A, or beta-carotene, in vegetable products.

Vitamin A properties

Vitamin A performs a number of important tasks in the body.

The most important functions and properties of vitamin A:

  • participation in protein synthesis and transformation of lipids (fats)
  • improving the regenerative capacity of cells
  • participation in the proper course of growth processes.
  • potential anti-cancer properties
  • vision improvement
  • skin renewal
  • anti-wrinkle effect - stimulation of collagen and elastin production in the skin
  • reducing the skin's sensitivity to UV rays.

Vitamin A and cancer

One of the most important properties of vitamin A is that it has a potential anti-cancer effect - it is believed to play a role in preventing and slowing down the progression:

  • colorectal cancer
  • prostate cancer
  • breast cancer
  • lung cancer

Vitamin A for he althy eyes

Vitamin A is part of rhodopsin (a visual pigment found in the rods of the eye's retina) and is involved in the process of seeing. A characteristic symptom of vitamin A deficiency is night blindness,called night blindness, caused by a rhodopsin deficiency.

Vitamin A - cosmetics and treatments

Vitamin A accelerates the renewal of the epidermis, strengthens its protective function and reduces water loss from the skin. It increases the production of collagen and elastin - the basic building blocks of the skin. In addition, it eliminates fine wrinkles and discoloration. As a result, vitamin A is one of the most effective ingredients in anti-aging preparations. Ointment with vitamin A or cream with vitamin A is a cosmetic that is worth having at home.

Vitamin A makes the skin supple, elastic and moisturized. Vitamin A has also been shown to help treat acne. In addition, beta-carotene, or provitamin A, is an additional "sunscreen" that reduces the sensitivity to UV radiation, and thus the risk of skin burns.

Treatments with retinol help solve many skin problems

Source: lifestyle.newseria.pl

Causes of vitamin A deficiency

Vitamin A deficiency in the body can be the result of:

  • Vitamin A malabsorption (then you should diagnose the underlying cause)
  • too poor diet (protein or fat deficiencies)
  • drinking alcohol
  • smoking
  • an unbalanced diet for children and the elderly

Symptoms and effects of vitamin A deficiency

Vitamin A deficiency in the body manifests itself:

  • very dry, even rough skin on the elbows and knees, as well as on the arms and thighs (skin dryness does not disappear after applying cream or lotion)
  • amblyopia at dusk and at night (so-called night blindness) and delayed eye accommodation in the dark (if it exceeds 10 seconds - it is a sign of vitamin A deficiency)
  • dry eyeball (no tears) - high deficiency of A can lead to drying out of the cornea and conjunctiva, and even to the cornea becoming cloudy and soft
  • decreased resistance to infections
  • growth inhibition
  • changes in the nervous system

In women, menstrual disorders and fertility disorders may be related to vitamin A deficiency. In the elderly, ringing in the ears is a common symptom of vitamin A deficiency.

Vitamin A deficiency symptoms

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Author: Time S.A

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Symptoms and effects of excess vitamin A

Vitamin Ain excessive amounts is a toxic compound . With its excessive consumption, the following appear:

  • irritability
  • gastrointestinal disorders
  • skin color change
  • liver enlargement
  • spleen enlargement
  • itchy skin
  • headaches
  • photophobia
  • convulsions
  • nail brittleness
  • hair loss

Vitamin A during pregnancy - its excess is particularly dangerous

Too much vitamin A is especially toxic to the fetus . Its overdose may cause the development of birth defects. For this reason, pregnant women should not reach for dietary supplements containing vitamin A, and also limit the consumption of meat containing vitamin A in the form of retinol (e.g. liver). However, you can eat any amount of vegetables and fruits containing beta-carotene. It is converted in the liver into vitamin A in the amount that the body needs. There is no possibility of vitamin A overdose when eating vegetables and fruit.

Vitamin A - dosage. Recommended Daily Allowance (RDA)

AgeDosage
children: from 1 to 3 years old400 µg; from 4 to 6 years of age - 450 µg; from 7 to 9 years of age - 500 µg
boys: 10 to 12 years old600 µg; from 13 to 18 years of age - 600 µg - 900 µg
girls - 10-12 years old600 µg; from 13 to 18 years of age - 700 µg
men900 µg
women700 µg
pregnant women19 years old - 770 µg
breastfeeding women19 years old - 1300 µg

It is worth knowing thatan increase in the need for vitamin Ais observed in people with digestive system diseases, during prolonged stress and infections, and when using a diet containing very small amounts of fat (5-10 g / d).

Source: Nutrition standards for the Polish population - amendment, Food and Nutrition Institute, Warsaw 2012

What products contain vitamin A?

Vitamin A occurs as retinol in products of animal origin and in the form of provitamin A, i.e. beta-carotene, in products of plant origin. These compounds have different biological activity.

Beta-carotene is to a lesser extentconsumed from food than retinol. It is assumed that the total utilization of beta-carotene is 6 times lower than that of retinol, and of other carotenoids 12 times. Therefore, the total content of vitamin A in food products is expressed in micrograms (µg) of retinol equivalent (equivalent).

Vitamin A content in selected foods

The content of retinol equivalents in 100gFood products
Less than 15 µgbeef, poultry meat (chicken and turkey breast), fish (cod, pollock, hake), lean curd cheese, natural yoghurt, kefir, pumpernickel bread, Kaiser rolls
15 - 150 µgveal, chicken, ducks, fish (herring, mackerel, salmon, trout, carp), fruit yoghurt, cow's milk and goat's milk, homogenized cottage cheese, semi-fat and fatty cottage cheese, Wrocław rolls, toasted bread, pasta two-egg and four-egg
150 - 1500 µgprocessed cheese, ripened cheese, eggs, margarine, butter, tuna, eels
Over 1500 µgchicken liver, pork and beef liver

"Vitamins", collective work edited by prof. Jana Gawęcki, Library of the Nutrition Knowledge Olympiad, Book 5, Department of Human Nutrition Hygiene, Poznań 2000

  • Vitamin D - dosage for infants, children and adults. Vitamin D Intake Standards
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  • Vitamin E - properties and application of vitamin E

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