July 21, 2000
NEW YORK (Reuters Health) - Taking a daily multivitamin in combination with one of the antioxidant vitamins A, C or E appears to reduce the risk of dying from heart disease and stroke, results of a study suggest.

However, this vitamin regimen may also increase the risk of dying from cancer in male smokers, the authors report in the July issue of the American Journal of Epidemiology.

The findings "warrant corroboration," write Margaret L. Watkins and colleagues from the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia. They call for further studies to examine the role that vitamins and vitamin combinations may play in dying from heart disease, cancer and stroke--the three leading causes of death in the US.

In the study, which included more than 1 million adults aged 30 and older, researchers compared death rates of those who used multivitamins alone; vitamin A, C or E alone; or a multivitamin with vitamin A, C or E; with death rates of people who did not take vitamins, over a 7-year period.

The investigators found that adults who took a multivitamin with an antioxidant vitamin had a 15% lower risk of dying from heart disease and stroke than people who did not take vitamins. Risk appeared to fall with time as individuals took the vitamin combination.

However, there was no survival advantage among people who took a multivitamin alone. "One explanation is that there may be a minimum dose of a single vitamin or combination of supplements necessary for risk reduction," the researchers suggest.

In other findings, the risk of death from cancer was the same among vitamin users and non-users. Use of multivitamins alone or with other vitamins seemed to increase the risk of dying from all cancers, compared with using vitamin A, C or E alone, the report indicates.

Male smokers who used multivitamins alone or in combination with other vitamins had a higher risk of dying from cancer than nonsmoking males who took vitamins. What's more, men who smoked and took vitamins had a higher risk of dying from prostate cancer than male smokers who did not take vitamins.

These findings support previous research demonstrating that high doses of beta-carotene can increase the risk of dying from lung cancer in male smokers. The authors suggest that the use of vitamin A, C or E may counterbalance the observed elevated cancer mortality risk among men who used multivitamins.

They also note that adults who took vitamins tended to be more educated and less overweight than those who did not. Vitamin-takers were also more likely to eat vegetables and drink wine or liquor.