Results of a large study published Wednesday in the Journal of the American Medical Association suggest that taking a daily multivitamin might reduce older men’s cancer risk — but not their ultimate risk of dying from cancer.

This Oct. 11, 2012 photo provided by the Brigham and Women's Hospital shows a monthly calendar vitamin pack used in a long-term study on multivitamins. (Associated Press)

The study didn’t detect reductions in risk for any single form of cancer, just the total risk of a cancer diagnosis overall. The findings held for the group of men who had never had cancer before entering the study and for the group of 1,312 who had. About half the cancers diagnosed among the men were prostate cancers (perhaps because the men were being diligently screened for that disease); the researchers ran the numbers again after removing those cases from the mix, and the results were unchanged.

The study adds to the growing body of science regarding vitamins’ potential role in preventing or protecting against disease. Research in this area has been conflicting and inconclusive, the study notes, with some studies finding various vitamins either reducing, increasing or having no effect on the risk of chronic diseases.

“Although the main reason to take multivitamins is to prevent nutritional deficiency,” the study concludes, “these data provide support for the potential use of multivitamin supplements in the prevention of cancer in middle-aged and older men.” The study also notes, “The reduction in total cancer risk [in this study] argues that the broader combination of low-dose vitamins and minerals contained in the PHS II multivitamin…rather than an emphasis on previously tested high-dose vitamins and mineral trials, may be paramount for cancer prevention.”

According to the study, about a third of U.S. adults use daily multivitamins — despite the statement in the Dietary Guidelines for Americans 2010 that “For the general, healthy population, there is no evidence to support a recommendation for the use of multivitamin/mineral supplements in the primary prevention of chronic disease.”

Do you take a daily multivitamin? Why or why not?