Vitamin A

Vitamin A, also known as retinol, occurs naturally only in animals. Eggs, liver, and milk provide much vitamin A. Some plants contain substances called carotenes, or provitamins A, which the body converts into vitamin A. These plants include cantaloupes, carrots, sweet potatoes, dark green leafy vegetables, and deep yellow vegetables.

Vitamin A is essential for the development of babies before birth and the growth of children. It is especially needed for the growth of bones and teeth. Vitamin A keeps the skin healthy and helps produce mucous secretions that build resistance to infection. People who do not get enough vitamin A may develop xerophthalmia, in which the surface of the eye becomes dry and likely to develop infection. Vitamin A also forms part of the two pigments that help the eyes to function normally in light that varies in intensity. Night blindness is an early symptom of a deficiency of vitamin A.