Vitamin A (Retinol)
Vitamin A has a number of varied functions in the body. It is necessary for growth and development. It helps to keep the skin and epithelial tissues healthy and resistant to infection.
Vitamin A occurs in the retina of the eye, as a part of substance rhodopsin or visual purple.
Visual purple is bleached in the presence of light and regenerated in the dark with the help of vitamin A.
Vitamin A is needed visual cycle, which enables a person to adjust to light of varying intensity. Thus, Vitamin A is needed for normal vision in light and darkness (night).
The earliest symptom of Vitamin A deficiency is night blindness, the inability to see normally in dim light.
Other symptoms of Vitamin A deficiency which develop progressively are dryness of conjunctiva, xerosis of cornea and corneal infection, which if unchecked may lead to blindness.
In addition, severe deficiency of Vitamin A results in growth failure and skin changes (dryness, wrinkling, thickness).
Being fat-soluble, vitamin A is present only in the fat of animal foods, such as whole milk products ghee, butter, egg yellow, liver etc.
A plant pigment (red-orange in color) called carotene is converted to vitamin A in the body.
Therefore, foods which contain carotene are indirect sources of vitamins A. Such foods include dark green leafy vegetables, such as amaranth, coriander drumstick, radish leaves and spinach, and orange-yellow vegetables and fruit, such as carrot, pumpkin, papaya and mango.
Severe deficiency of vitamin A leads to growth failure skin changes infections of the eye and eventual loss of vision.
Vitamin A (Retinol)
