In addition to treating deficiency syndromes, vitamin A has several potential preventive and therapeutic uses. Vitamin A is important "medicine" for the immune system. It keeps skin and mucous membrane cells healthy. When membranes are healthy they stay moist and resistant to cell damage. The moistness inhibits bacteria and viruses from "putting down stakes" and starting infectious diseases.

Healthy cells are also resistant to cancers. Vitamin A fights cancer by inhibiting the production of DNA in cancerous cells. It slows down tumor growth in established cancers and may keep leukemia cells from dividing.

This vitamin is particularly helpful in diseases caused by viruses. Measles, respiratory viruses, and even human immunodeficiency virus (HIV), the virus that causes AIDS, may retreat in the presence of vitamin A. Blood levels of vitamin A are often low in people with viral illnesses. After receiving additional amounts of this vitamin, the body is able to mount its defenses, often resulting in a quicker recovery. However, vitamin A can also increase the risk of infections, according to the findings of a recent study. In HIV infection, for instance, preformed vitamin A may also encourage HIV to replicate, so limiting the intake of vitamin A is the best bet for these patients.

Stroke victims who have high levels of vitamin A in their systems are less likely to die or suffer disabilities from the stroke. Eating plenty of fruits and vegetables is a good defense against stroke and its complications.

Topical application of vitamin A helps relieve dry-eye disorder. When tear production and lubrication stop, the resulting dry eyes can be extremely uncomfortable. Many treatment avenues are often disappointing, with the exception of vitamin A eyedrops. Used clinically, these drops improve cell function and moistness returns to the eyes. Vision Pharmaceuticals (1-800-325-6789) sells vitamin A drops called Viva-Drops in many chain drugstores throughout the U.S.

Vitamin A taken orally and applied topically looks promising in preventing and possibly even treating skin cancers. It may be helpful, too, in lightening liver spots, those dark spots that often appear on aging skin. Topical application used in one study significantly lightened liver spots within one month.

Vitamin A derivatives are used to treat skin disorders. Isotretinoin acne medicine is an oral medication used for severe cystic acne. Because of the possibility of such serious side effects as liver damage and elevated blood triglycerides, a doctor must closely monitor treatment with this medication. Any woman capable of becoming pregnant needs to use reliable birth control when taking this medicine because it can cause spontaneous abortion or serious birth defects. Pregnant women must avoid it and other sources of high-dose vitamin A.

Tretinoin is a topical medication primarily used for acne, with less potential for serious side effects than oral isotretinoin. It treats baldness when prescribed along with minoxidil. It also may reduce the appearance of wrinkles and reverse the effects of sun damage on the skin. Another vitamin A derivative, etretinate, may treat psoriasis.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.