VITAMIN A - RETINAL
Vitamin A, also called as retinol, is a fat-soluble substance that is important for vision and for the membrane integrity, especially of epithelial cells and mucous membranes. It is thus known to prevent premature aging process of the skin. It is also essential for bone growth, reproduction and embryonic development. It has also been called the anti-infective vitamin and its deficiency can lead to increased frequency of respiratory tract and gastrointestinal infections.
The natural sources of vitamin A are alfalfa, animal livers, apricots, asparagus, beans, beets, broccoli, cabbage, cantaloupe, carrots, cod liver oil, dandelion green, dates, egg yolk, fish and fish liver oils, yellow and red fruits (like apricots, melon and pumpkin), dark green leafy vegetables (especially spinach, spirulina, turnip tops and green peas), garlic, kale, milk and milk products (especially butter and cheese), mustard, oranges, papayas, parsley, peaches, pumpkin, red palm oil, red pepper, soya beans, sweet potatoes, tomatoes, watercress (Jalkumb) and whole cereals.
The deficiency of vitamin A when mild, causes dryness, itching and peeling of the skin, problems in the teeth, bones, soft tissues, digestive tract, allergies, gallstones, etc. It is also useful to resist colds and improve immunity. In severe deficiencies, there are visionary disorders like myopia, night blindness, xerophthalmia (dryness and thickening of the bulbar conjunctiva of the eyes with formation of triangular Bitot's spots), keratomalacia (the cornea undergoes ulceration and necrosis), etc. Also the tissues of the body get damaged leading to recurrent infections of the mouth, respiratory organs, Genito-urinary tract, etc.
Hypervitaminosis A is especially common in children who have been given excessive amounts of vitamin A over a long period of time. The symptoms include irritability, nausea, vomiting, loss of appetite, headache, liver damage, dryness and scaling of skin and in rare cases an increased intracranial pressure.
