Fat soluble vitamins:
They are dissolved in fat and reserved in the body for a whole day or almost a month. They are storage in the fatty tissues as well as in the liver. Vitamin A, D, E and K is a fat soluble vitamin. They are absorbed in the GI tract with the help of fat. They are eliminated much more slowly than water-soluble vitamins.
Vitamin A:
Vitamin A also called Retinol plays an important role in bone growth, tooth development, cell division, reproduction, gene expression and immune function. It plays role in the prevention of certain cancer as an antioxidant. Skin, eyes, mucous membranes depend on vitamin A to keep moist.
Structures of vitamin A:
Food sources:
Some dark orange and green vegetables contain an antioxidant called Beta- carotene which the body convert to vitamin A. Vitamin A sources also include carrots, pumpkin, winter squash, dark green leafy vegetables etc.
RDA (Recommended dietary allowance):
The Recommended dietary allowance for vitamin A is 900mcg/day for adult male and 700mcg/day for adult women.
Vitamin A deficiency:
Xeropthalmia most commonly occurs in the developing nations usually due to malnutrition. Night blindness and very dry, rough skin indicate a lack of vitamin A.Other possible vitamin A deficiency include that slower bone growth and tooth development as well as decrease resistance to infections.
UL (Upper intake level):
Tolerable upper intake level for an adult is 3000mcg RAE.
Symptoms of toxicity:
Symptoms of vitamin A toxicity include dry, itchy skin, headache, nausea, and loss of appetite. Vitamin A toxicity also causes severe birth defect and may increase the risk of hip fractures.
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