A daily multivitamin can help a man reduce his risk of cancer, according to a new study published online Wednesday in the Journal of the American Medical Association.

Researchers had nearly 15,000 men over the age of 50 take either a multivitamin or a placebo every day for more than 10 years. The men self-reported a cancer diagnosis, and researchers confirmed the diagnosis through medical records.

Researchers found the group taking a daily multivitamin had an eight percent reduction in total cancer compared with the group taking the placebo. They also found a multivitamin was associated with an apparent reduction in cancer deaths.

"Many studies have suggested that eating a nutritious diet may reduce a man's risk of developing cancer. Now we know that taking a daily multivitamin, in addition to addressing vitamin and mineral deficiencies, may also be considered in the prevention of cancer in middle-aged and older men," said study coauthor Howard Sesso, an associate epidemiologist at Brigham and Women's Hospital in Boston.

Researchers point out that it is not clear which specific vitamins or minerals in a multivitamin may be responsible for the reduction in cancer risk. Also, it is not known if the results can extend to women or to men younger than the age of 50. Researchers plan to follow up with study participants to determine the affect of a daily multivitamin on cancer over an even longer period of time.

A similar study is examining the affect of daily multivitamin use on cardiovascular disease risk. Results of that study will be announced at the American Heart Association Scientific Sessions in early November.