The most common supplement -- the multivitamin -- appears to do more than just make up for dietary nutrient shortfalls. A new study found that it “modestly but significantly” reduced the risk of cancer in men.

The study followed more than 14,000 doctors over the age of 50 for an average of 11 years. Each was given either a multivitamin or a placebo to take every day.

At the end of the follow-up period, men who took the multivitamin had their risk of developing cancer reduced by about 8 per cent.

Lead researcher Dr. Michael Graziano, of Boston’s Brigham and Women’s Hospital and Harvard Medical School, said that “the main reason for taking a multivitamin is still to prevent vitamin and mineral deficiencies.”

However, “our data suggest there may be a benefit in terms of preventing cancer, at least in middle aged or older men,” he said.

The findings were presented Wednesday at the American Association for Cancer Research conference on cancer prevention in California. The study is also published in the online edition of the Journal of the American Medical Association.

In their study, the researchers noted that “observational studies of long-term multivitamin use and cancer end points have been inconsistent.” And large-scale, randomized trials looking at individual vitamins and cancer “have generally found a lack of effect.”

There is also little evidence to suggest multivitamins protect against chronic disease, though many people take them for that very purpose, researchers said.

But the study found that after the follow-up period, there were 2,669 new cancer cases. Per year, there were 17 cancers diagnosed per 1,000 men in the multivitamin group, and more than 18 cancers in the placebo group.

Multivitamins appeared to do little to reduce the risk of developing prostate cancer. However, when prostate cancer is removed from the data, multivitamins lowered the risk of other cancers combined by about 12 per cent.

One of the study’s limitations is that only men were included, and so it is unclear whether multivitamins may show the same cancer-prevention effects in women. And it must be noted that drugmaker Pfizer Inc. supplied the pills.

But the findings suggest that taking a multivitamin can’t hurt.

Nutritional consultant Aileen Burford Mason said that in her practice, she touts the multivitamin as “the one supplement that everyone will benefit from” because it has “a little bit of everything.”

With a report from CTV’s medical specialist Avis Favaro and producer Elizabeth St. Philip and files from The Associated Press