|What is |
Vitamin A is a fat-soluble vitamin also known as retinol that is necessary for proper vision in the eye especially night vision.
What are the
functions of vitamin A?
Vitamin A helps to prevent night blindness. It also helps keep the skin, lungs, intestine, and urinary tract healthy and protects against infections. Vitamin A also acts as an antioxidant.
Which are the
forms of vitamin A available for consumption?
Vitamin A is available in food in 2 forms. Retinol which is preformed vitamin A occurs only in foods of animal origin. Fruits and vegetables have vitamin A in the form of carotenoids. Carotenoids are plant pigments, responsible for the red, orange, and yellow color of fruits and vegetables. Once consumed, carotenoids are slowly converted to vitamin A in the body.
How does vitamin A act in the body?
The body converts vitamin A to retinol in the small intestine. The retinol functions as storage form of the vitamin, and can be converted to its visually active form, retinal whenever required.
Which foods are rich in vitamin A?
Animal sources of vitamin A (contain preformed vitamin A) are cod liver oil, kidney, egg yolk and butter. Provitamin A carotenoids are found in plants, mostly in green leafy vegetables like broccoli, spinach and carrots. Carotenoids are best absorbed from cooked or homogenized vegetables served with some fat or oil. Conversion of carotenoids to vitamin A is controlled by the body and thus overdosage with carotenoids does not occur. Animal sources of vitamin A are preformed vitamin A and thus can lead to overdosage.
What is the
daily requirement of Vitamin A for a normal individual?
Daily requirement of vitamin A is 4-8mcg/day for children upto 8 years of age and 600-700mcg/day for older children.
My child does not eat fruits and vegetables. Will he get vitamin A deficiency?
Vitamin A deficiency may result from a diet deficient in fresh fruits and vegetables. Vitamin A deficiency is estimated to affect approximately one third of children under the age of five around the world.
What happens if vitamin A is deficient in the diet?
Vitamin A deficiency can affect the immunity, the vision and skin, lungs, urinary tract. It leads to night blindness which may ultimately lead to permanent blindness. Drying, scaling of the skin can occur and child can get respiratory infections. Due to rampant Vitamin A deficiency in India, the national immunization programme has recommended that at the age of 9 months, infants should receive 1 lakh IU of vitamin A with measles vaccine.
What happens if
overdosage of vitamin A occurs?
Accidental ingestion of high dose of vitamin A can lead to headache and increased pressure in the brain (pseudotumor cerebri). Long term ingestion of high dose of vitamin A can lead to alopecia, visual impairment, dry itchy skin, weight loss and even fractures. Pregnant women who require vitamin A supplementation should not given high-dose supplements due to potential side effects in the fetus.