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What is
it?
Vitamin A is the name given to
a group of related compounds (retinol, retinal and retinoic
acid) that have certain actions in the body. Vitamin A, like
other vitamins, is required in small amounts by our bodies
to function and develop properly. Because we cannot
synthesize vitamin A, we must obtain it through our diets.
What Does
in the Body?
Vitamin A is used for two
functions in the body. Used in the eye, it is a component of
the eye's light-sensitive parts, containing rods and cones
that allow for night-vision or for seeing in dim-light
circumstances. Vitamin A (retinol) occurs in the rods.
Another form of Vitamin A, retinoic acid, is used in the
body for regulating the development of various tissues, such
as the cells of the skin, and the lining of the lungs and
intestines
Where is it found?
The best sources of vitamin A are eggs, milk, butter, liver,
and fish, such as herring, sardines, and tuna. Plants do not
contain vitamin A, but they do contain beta-carotene and
other carotenoids. The best sources of beta-carotene are
dark-green, orange, vegetables, carrots.
Recommended Daily Intakes: men
10 mg, women 0.8 mg, pregnancy: 0.8 mg, lactation 0.8 mg.
Symptoms Of
Deficiency/Side Effects
Vitamin A deficiency occurs with the chronic consumption of
diets that are deficient in both
vitamin A and
beta-carotene. When vitamin A deficiency, it tends to happen
in alcoholics or in people with diseases that affect the
intestine's ability to absorb fat. The earliest symptom of
vitamin A deficiency is night blindness. |