Alternate Names : Retinol, Retinal, Retinoic Acid, Carotenoids Including Beta-Carotene
Vitamin A is a fat-soluble vitamin which means it can be
dissolved in fat. Vitamin A is carried through the body by fat. The
body can store this type of vitamin in fat tissue. Getting too much
can be harmful.
Vitamin A is usually measured in retinol equivalents, also called RE.
The Recommended Dietary Allowance, called RDA,
for vitamin A for adult men, from age 11 on, is 1,000 RE per day.
Women, from age 11 on, should get 800 RE per day. There is no
increase of vitamin A requirements during pregnancy but lactating
women need about 500 RE or more per day.
Vitamin A can be stored in the fat tissues of the body.
This can pose a problem for people taking extra doses of vitamin A.
High doses can be toxic and cause symptoms such as the following:
dry and scaly skin
bone and joint pain
vomiting or lack of appetite
abnormal bone growth
In most cases, only levels 10 times the RDA (far more than a
person could get through diet alone) have been linked with these
symptoms. Vitamin A cannot reach toxic levels unless a person is
taking extra doses. Carotenoids are not converted to vitamin A
fast enough to increase the amount of vitamin A stored in the body.
Beta-carotene is NOT toxic to the body.
Getting too little vitamin A can cause side effects too.
Symptoms of significant deficiency include:
lowered resistance to infections
problems with getting pregnant
improper tooth formation
rough, dry, and pimply skin
eye disease, including xerophthalmia (zear-off-thal-me-ah), a
condition in which the clear covering of the eye known as the
cornea becomes dry and dull
Vitamin A is an important fat-soluble vitamin. Eat a
variety of fruits, vegetables, lean meats, and fortified dairy products
to ensure optimal intake of vitamin A. Read food labels to help
choose foods with vitamin A content.