Vitamin A as "anti-infection" vitamin and cure for eyes

Vitamin A is known for its anti-infection role.Vitamin A is needed for formation of healthy epithelial surfaces which are the first line of natural barriers of infection that resists invasion by pathogenic organisms.

Important: Once infection occurs,vitamin A has no effect against infection.The anti-infection role is preventive not therapeutic!

Vitamin A has sources in animal and plant foods.
1.Animal Food: liver,egg yolk,whole milk and cheese,butter,cream and fatty fish.
2.Plant foods: plants don't provide vitamin A,but the vitamin precursor (provitamin) carotenes are converted in the body into vitamin A.Carotenes are found in pigments of most vegetables and fruits (green,yellow,red,orange).The Beta-Carotene found in leafy vegetables is particularly important.

One other rich source of vitamin A is the cod liver oil and other fish liver oils that can be given as supplement of vitamin A.

Functions of Vitamin A:
Vitamin A is responsable with the growth of healthy ephithelial cells of skin and mucous membranes,specially of respiratory passages and urinary tract.The vitamin A has the anti-infection role in this case.
The vitamin A is responsabe with the normal secretion of lacrimal glands.Deficiency of vitamin A leads to xerosis and lack of tears whit the risk of eye infection.
Vitamin A is a component of visual purple of the retina that is needed for vision in low-intensity light.Deficiency of vitamin A leads in an early face to impaired dark adaptation or severe case of night blindness.