This article is from the WebMD Feature Archive

People seem to be more interested in good nutrition than ever before.

Since childhood I was always told, "Eat a well-balanced diet and you won't need to take any additional vitamins." Health experts now dispute this advice and claim consumption of extra vitamins and nutrients can prevent or slow the development of many diseases.

A daily multivitamin is a good place to start. The manufacturers have already done the choosing for you. When you see the data on the label regarding Percent Daily Value, remember this was information concocted by a committee -- a consensus of experts. Some experts fought to make the number much higher, others wanted lower figures. Some people disregard these tables and buy separate nutrients, mega-doses of vitamin A, etc.

Now we are encouraged to buy eye vitamins. These supplements are not a traditional multivitamin. In fact, the makers of products like Ocuvite and ICaps recommend you take their pill in addition to a daily multivitamin.

There are several strong reasons to consider these products. The healthy eye needs lots of vitamins and nutrients to function, to protect itself from degeneration, and to prevent the development of future eye disease.

Right off the top, vitamins A, C, D, and E are critical to your vision. Interestingly, A, D, and E are metabolized by the liver -- so don't overdo it or you could hurt yourself. Vitamin C is water soluble -- what you do not use is eliminated in urine.

Next come the other nutrients: selenium, lutein, zinc, and many others. What most have in common is their ability to help the cells efficiently manage their metabolism and chemical wastes.

Lutein is a naturally occurring chemical that is touted for its antioxidant capabilities. It is sold separately as a nutritional supplement and included in many combination products as well. During normal cell metabolism, chemical reactions occur that release activated molecules that will, over time, lead to cell degeneration. Antioxidants such as Lutein are scavengers that neutralize these "free radicals" and prolong the life of the cell. That's the theory, anyway.

Vitamins and other nutrients work best when consumed throughout life, not beginning at age 60. Laboratory studies show that antioxidants can halt tissue degeneration. Based on that data, doctors recommend antioxidants to protect patients from serious eye conditions such as macular degeneration.

There are no clinical studies in the peer-reviewed medical journals that prove any of this. Many of the results are anecdotal. Nevertheless, most authorities suggest there is a likely benefit.

Are these products worth buying? It may take another 20 or 30 years of clinical research to definitively prove their value. But by waiting until then it may be too late to make a difference in your life. It's a decision you'll need to make today.

Bill Lloyd, MD, is an experienced ophthalmologist who has devoted the last two decades to practicing and teaching medicine.

The opinions expressed herein are the guest's alone and have not been reviewed by a WebMD physician. If you have a question about your health, you should consult your personal physician. This event is meant for informational purposes only.

Originally published Oct. 7, 2002.