Study: Long-Term Use of Multivitamins May Cut Colorectal Cancer Risk

Taking multivitamins regularly for a decade appears to reduce the risk of colorectal cancer, but any protective effect does not occur quickly, according to researchers.

The findings from the Cancer Prevention Study II Nutrition Cohort, which examined the relationship between use of multivitamins and colorectal cancer among more than 145,000 predominantly white adults, were reported in the American Journal of Epidemiology.

Approximately half of the participants in the study reported no multivitamin use, 8 percent said they took a multivitamin regularly in the past, and 19 percent said they started regularly taking a multivitamin recently.

After adjusting for other factors, the researchers concluded that participants who regularly took multivitamins four or more times a week 10 years prior to the start of the study had a 30 percent lower risk of developing colorectal cancer.

But those who had only recently begun taking multivitamins showed to risk reduction, the researchers said.

"These results are consistent with the hypothesis that past, but not recent, multivitamin use may be associated with modestly reduced risk of colorectal cancer," the researchers concluded.

Other sources: American Journal of Epidemiology