A is used by the body for normal growth, and for the production
and maintenance of skin, teeth and bone. The form of vitamin
A found in mammals is called retinol. The body makes vitamin
A from carotene, which is found in the yellow pigment of some
plants. Good sources of vitamin A are thus yellow and yellow-orange
fruits and vegetables (squash, oranges, cantaloupes, etc.),
as well as butter, egg yolks, and cod liver oil.
A deficiency in vitamin A causes interference
with growth, reduced resistance to infections, night blindness
and impaired visual acuity. Vitamin A is also an anti-oxidant,
and so it is thought to be helpful in preventing cancer. Excessive
intake of vitamin A can be toxic, so megadoses are not recommended.
by Catherine E. Myers. Copyright © 2006 Memory Loss and the Brain