Vitamin A sources, function, deficiency, excess diseasesVitamin A is essential for normal growth and development. It is also known as retinol. It has given this name due its role in the formation of pigment of retina. Retina is the innermost layer present in the eye ball on which visual image is formed. Vitamin A exists in both pure and pro form. When you take pro form of vitamin A, It converts into Vitamin A inside the body.

Functions of Vitamin A

Vitamin A, has a major role in vision. It is essential for the proper functioning of retina. Moreover, vitamin A promotes growth of hair, teeth and skin. It boosts immunity and protects from infectious diseases. Moreover, it has also a role in proper functioning of reproductive system.

Sources of Vitamin A.

Vitamin A is mainly found in following substances.

Dark green leafy vegetables e.g, spinach, pumpkins, Lettuce, Carrots are rick in beta-carotene which is a pro-vitamin A substance and It converts into vitamin A inside the body. Sweet potatoes, yellow colored ripe yellow fruits e.g, orange, apricot and grapes are also rich sources of preformed and pro-vitamin A. Meat, fish liver oil, poultry and diary products also are the rich sources of vitamin A.

Daily Requirement of Vitamin A.

Adults need 700 – 900 micrograms of vitamin A per day. Children needs 300 – 600 micrograms per day and infants need 400-500 micrograms of vitamin A per day.

Deficiency of Vitamin A and the diseases.

As vitamin A is required for vision, growth, immunity, skin, hair and reproductive  health, therefore, its deficiency results in vision problems (night blindness), skin diseases (hyperkeratosis), hair loss, and vulnerability to infections.

Excess or over dose of Vitamin A.

Excess of over-dose of vitamin A cause headache, dizziness, nausea and vomiting, in short words it makes you sick. Usually overdose means taking more than 25,000 international units of vitamin A per day for one to two weeks. This is a large amount and usually we don’t get over dose of vitamin A by taking normal foods. Overdose occur in those who are taking vitamin A rich supplements, or by accidental ingestion of vitamin A tablets by children.

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