Vitamin A (also called retinol, beta-carotene, axerophthol and provitamin A) is a fat soluble vitamin facilitating proper vision, strengthening immunity and maintaining good skin condition. It is necessary for the proper metabolism of proteins and steroid hormones. Vitamin A takes a significant part in the visual process because it is part of rhodopsin – a visual pigment found in the eye. A characteristic symptom of deficiency of this vitamin is twilight blindness, called nyctalopia , caused by rhodopsin deficiency.Vitamin A also participates in building the body’s natural immunity and is essential for the proper formation of plaque.One of the most well-known properties of this vitamin is its beneficial effect on the skin. It protects the skin against UV radiation, regulates skin exfoliation disorders, reduces hyperkeratosis, or thickening of its top layer, and at the same time renews alive and well moisturized epidermis.
Symptoms of Vitamin A deficiency:
Symptoms of vitamin A deficiency may be as follows:
- fragile and brittle nails,
- dry and brittle hair,
- rough skin,
- loss of half of visual field at dusk and at night (the so-called nyctalopia and delayed accommodation of the eye in the dark (if it exceeds 10 seconds – it is a sign of vitamin A deficiency),
- rashes on the body,
- loss of apetite,
- weakened immunity,
- feeling tired,
- inhibition of growth,
- changes in the nervous system,
- menstrual and fertile disorders.
Symptoms of excess amount of Vitamin A:
Vitamin A in excess amounts is a toxic compound. Excessive consumption may cause:
- change in skin color,
- itching of the skin,
- gastrointestinal disorders,
- enlargement of the liver and spleen,
- brittle nails and hair loss.
Excess vitamin A is extremely toxic to the fetus. Overdose of this vitamin may cause development of fetal malformations. Therefore, pregnant women should not use dietary supplements containing vitamin A, as well as limit meat consumption, which contains vitamin A in the form of retinol (e.g. liver). It is not possible to overdose of vitamin A by eating fruit and vegetables because in fruits and vegetables vitamin A is found in the form of beta-carotene, which is converted in the liver into vitamin A in the amount that the body needs.
Sources of Vitamin A in food:
Fish, egg yolk, butter, giblets (e.g. liver), cheese, milk, wild rose fruit, nettle, spirulina, black elder, carrots, tomatoes, spinach, lettuce, green peas are all sources of vitamin A.Plant products rich in provitamin A include yellow, orange, red and dark green fruits and vegetables, among others carrots, pumpkin, spinach, tomatoes, apricots, plums, lettuce, green peas, dill, parsley.
Supplementation with Vitamin A:
Supplements which contain Vitamin A:
Preparations with vitamin A should not be used by pregnant women, because it can cause the development of fetal malformations. People with cirrhosis, patients with hepatitis, and people with hypertension should pay special attention to such preparations.