As many as 10 percent to 15 percent of individuals over age 70 have significant deficiencies of vitamin B-12.

This condition can lead to several health problems, including anemia, fatigue, depression, difficulties in gait and balance and declines in memory. It also leads to an increased concentration of homocysteine, an amino acid that when elevated is associated with risk of coronary artery disease, stroke, depression and Alzheimer's disease. As decreased levels of vitamin B lead to increased levels of homocysteine, scientists have questioned whether the inverse is true as well. Can increased vitamin B lead to decreased levels of homocysteine and thus lower the risk of disease?

There is now good evidence that combining vitamin B-12 with two other B vitamins, folic acid and vitamin B-6, is extremely efficient in lowering homocysteine to normal levels. As a result, many physicians routinely screen patients for increased homocysteine levels. If elevated levels are present, doctors typically prescribe an expensive medication that combines the three B vitamins in the ideal doses.

Patients may spend years on this medication with the hope that it can decrease the risk of illness. Unfortunately, this may not be true, and it is very expensive.

Although we know that increasing vitamin B can decrease homocysteine, it is still unclear whether this has any effect on reducing the risk of illness. In the past few weeks a research study published in the Journal of the American Medical Association examined the role of vitamin B treatment on 3,100 patients with proven heart disease. These patients did not necessarily have vitamin B deficiencies.

Three quarters received a mix of B-12, folic acid and B-6, and the remainder received a placebo. Although homocysteine levels were lowered by 30 percent, treatment with the B vitamins did not prove to be of any value in reducing the risk of further heart disease. This study was stopped early because no benefit was noted and there was a suggestion that supplementation with B vitamins, more specifically with folic acid, may increase the risk of cancer.

During the same week, an article published in the Archives of Neurology showed that the use of these B vitamins was of no value in improving symptoms of depression in symptomatic patients.

While the link between vitamin B and increased homocysteine is clear, we still do not completely understand why lowering the amino acid does not seem to reduce risk of disease. Based on this information, it is not rational to prescribe the expensive vitamin B medication to lower homocysteine in the hopes of reducing risk of heart disease, stroke or behavioral problems. Taking extra doses of vitamin B should not be a mainstay of preventive medicine.

The evidence is clear that for adults without vitamin B deficiency, the supplement has no proven benefit and may be harmful. This should come as no surprise, as we already know that high doses of vitamins C, A and E increase the risk of heart disease and cancer. And now there is a suggestive link between too much folic acid and colon cancer.

In general, deficiencies in vitamin B are extremely rare for individuals under age 70. However, if you are over 70, go to your physician and request that the vitamin levels in your blood be measured. If the value is close to or below the lower limit of the normal range, a pill containing 500 micrograms of vitamin B-12 should be taken daily. This is much higher than the amount required to prevent deficiencies, but low doses cannot be absorbed from the bowel. If your blood level is normal, taking additional vitamin B-12 will not benefit you in any way.

For the sages of our community, I do recommend a daily multivitamin without iron. These pills do not contain excessively high doses of any vitamin or mineral and are almost certainly without side effects. Ultimately, these supplements simply act as insurance against deficiencies. The average diet of virtually every American contains more than sufficient amounts of vitamins and minerals to meet our bodies' needs. Only if one is deficient should supplements be taken. In the case of vitamin supplements, too much of a good thing is just too much.

Dr. David Lipschitz is the author of the book "Breaking the Rules of Aging." To find out more about Dr. David Lipschitz and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at www.creators.com. More information is available at www.drdavidhealth.com.

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