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A vitamin
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The A vitamin can be found in the human body in three different shapes: Retinol, retinal and retinoic acid.Vitamin A can be found in liver, butter, eggs, green and yellow vegetables, as sweet potato, carrot, apricot, mango, papaya or tomato. Because A vitamin can be lost during cooking, especially frying, it is recommended as to steam vegetables and braise, or bake them.A person needs between 1-6 mg per day.In vegetables aliments, the A vitamin can be found like precursor, called carotene, especially, beta carotene.In animal aliments the A vitamin is found like retinol with fats acids. The A vitamin is very important to the organism because of the multiple roles that it has. It is useful in development and maintenance of healthy skin and hair, reproduction, immune function, has role in vision and growth and also in maintenance of mucous membranes. With E vitamin can prevent cancer, it is also involved in seeing and can be used in treatment of acne and psoriasis. Also A vitamin is involved in developing of the red blood cells. It helps the Stem cells, the first cells of the organism, to difference into the red blood cells, among with the other cells that are developing from stem cells. A vitamin helps also iron to be integrated into the erythrocyte so that the cell can do it function of oxygen transporter. This is why, in anemia caused by lack of iron a treatment with iron and A vitamin is more effective than iron alone or A vitamin alone. The lack of A vitamin causes hemeralopia, a disease characterized trough the lack of seeing in the night, can cause sterility, infections or even blindness.Eyes that tires easily and are dry and itchy, is a signal of too little A vitamin. If no action is taking, it can appear an ulcer at the cornea, leading to permanent blindness.Also insomnia abscesses forming in the ear or fatigue can represent A vitamin deficiency. To much A vitamin is also damaging for the body. By eating too many carrots or having an inappropriate quantities of A vitamin ingested, they will cause the appearance of a yellow-orange coloring of the skin, first in the palms of the hands and the soles of the feet. This is different from jaundice, that is a disease that affects liver and is characterized also by the yellow coloring of the skin, but in this disease, the sclera remains white. But carotenemia has no bad consequences over the body, because the transformation of carotenes to retinol is not so toxic to harm the body. By ingesting, accidentally, a large amount of A vitamin, it appears the acute A vitamin toxicity.This is manifested by abdominal pain or vomiting, nausea, headache, muscle and bone tenderness and even neurological problems. Chronic toxicity with A vitamin is characterized by conjunctivitis, alopecia, ataxia or diplopia.Some studies showed that using A vitamin supplements can increase the risk of lung cancer, although the effect of A vitamin seems to be different in the smoker and non-smoker persons. Chronic alcohol consummation affects also the liver but also the A vitamin deposited. Alcohol, by destroying liver cells and affecting its functions, also causes the depleting of A vitamin deposite from the liver, causing an A vitamin deficiency. This is why persons that consume alcohol need more of A vitamins. Also persons that are following a low-fat diet or they smoke or live in polluted zones need to take an A vitamin supplements for maintenance of a adequate A vitamin level in the body, knowing that the human body can not synthesize any of the vitamin group.
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