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Foods that give vitamin A By Mumtaz Khalid Ismail
More Links Absorption and storage Dietary sources Carotene content of foods Vitamin A deficiency can lead to Toxicity Losses in preparation
Vitamins have been one of the major nutritional discoveries of the 20th century. Health foods and cosmetics started promoting the vitamins. Vitamins cannot synthesise in the body in adequate amounts and therefore it should be supplied in food. Deficiency of vitamins leads to various illnesses. Few of the vitamins are soluble in water where as some are soluble only in fat.
Vitamin A is a fat-soluble vitamin. MC Collum and Davis discovered this vitamin in 1913 at John Hopkins University in America, when they isolated a growth factor in egg yolk, butter, and cod liver oil. In 1920 Rosenhein and Drummond demonstrated the relationship of vitamin A to the plant pigment carotene. Carotene is a precursor of vitamin A in the body and is therefore known as pro-vitamin A.
Carotene is present in green and yellow vegetables and yellow fruits. Animals do not produce this. Carotene has alpha, beta, and gamma isomers. Among these isomers beta-carotene is the most widely distributed in food and more effectively converted into vitamin A. It does not get destroyed at ordinary levels of heat.
Vitamin A plays an important role in various functions of the body. It plays an important role in maintaining proper vision. This vitamin is required for formation and integrity of the epithelial tissue result in a healthy glowing and soft skin. It is required for proper growth and development of skeletal system of the body. Role of this vitamin in the immunological defence mechanism of the body is very important. Beta-carotene also has an important role as an anti-oxidant. Studies have shown that diets high in carotenoids are often associated with a reduced risk of certain cancers. This protection is however seen only if the source of beta-carotene is a food, and not the supplements.
Source Carotene content
ug /100gVitamin A equivalent
(ug) Per 100gRed palm oil 25,000-33,000 4167-5500 Green leafy vegetables Amaranth leaves 1,600-7,000 266-1166 Cabbage 1300 217 Coriander leaves 7,000-8,000 1166-1333 Curry leaves 8,000 1333 Drumstick leaves 7700 1283 Fenugreek leaves 2700 450 Radish leaves 4500 750 Mint 1800 300 Spinach 3600 600 Other vegetables Carrot 1,300-2,600 217-434 Pumpkin, yellow. 600-720 100-120 Fruits Jack fruit 320 54 Mango, ripe 3000 500 orange 210 35 Tomato ripe 190 32
*Source -Food & Nutrition Dr.M.Swaminathan
- Night blindness
- Bitot's spot
- Xerophthalmia
- Xerosis conjunctiva
- Xeroasis cornea
- Keratomalacia
- Follicular hyper keratosis or phrynoderma
Consumption of excess of vitamin A causes headache, fatigue, irritability, nausea, vomiting, and anorexia, which will disappear on withdrawal of vitamin A in take.
Vitamin A and carotene are stable to ordinary cooking methods, though some loss may occur at temperature above 100 degree Celsius as when butter or palm oil is used for frying. Fruits and other foods that are dried in the sun lose much of their vitamin A. Considerable losses of vitamin A may occur in fish liver oils bottled in colourless glass.
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Vitamin A is present in animal foods like whole milk, curd, butter, ghee, egg yolk, and liver. The liver oils of certain fish like cod halibut and shark are the richest sources of vitamin A. Spinach, amaranth, coriander leaves, curry leaves, drumstick leaves, ripe mangoes, papaya, fresh apricot, orange, raspberry, carrot, yellow pumpkins, mint, lettuce and tomato are rich in carotene. Among pulses red gram and masoor dhal has most carotene content.
