NMA: Nonprescription Medicines Academy

Daily Multivitamin Use Reduces Cancer Risk But Not Cardiovascular Risk in Men

December 14th, 2012

Among participants in the Physicians’ Health Study II—a large-scale, randomized, double-blind, placebo-controlled trial that included 14,641 male U.S. physicians 50 years of age or older—taking a daily multivitamin did not reduce major cardiovascular events, myocardial infarction (MI), stroke, or cardiovascular disease (CVD) mortality after more than a decade of treatment and follow-up. However, daily multivitamin use did modestly but significantly reduce the risk of total cancer.

The Physicians’ Health Study II began in 1997, with continued treatment and follow-up through June 1, 2011. The study population included 754 men with a history of CVD at randomization as well as 1,312 men with a history of cancer. As part of a 2x2x2x2 factorial design, participants were randomly assigned to a multivitamin group (Centrum Silver) or placebo group. The main CVD outcome measure was the composite end point of major cardiovascular events, including nonfatal MI, nonfatal stroke, and CVD mortality; secondary outcomes included MI and stroke individually. The main cancer outcome measure was total cancer (excluding nonmelanoma skin cancer), with prostate, colorectal, and other site-specific cancers among the secondary end points.

During a median follow-up of 11.2 years (interquartile range, 10.7–13.3 years), there were 1,732 confirmed major cardiovascular events and 2,669 confirmed cases of cancer, including 1,373 cases of prostate cancer and 210 cases of colorectal cancer. Compared with placebo, there was no significant effect of daily multivitamin use on major cardiovascular events (11.0 and 10.8 events per 1,000 person-years for multivitamin vs placebo, respectively; HR, 1.01; 95% CI, 0.91–1.10; P = 0.91). Further, daily multivitamin use had no effect on total MI (3.9 and 4.2 events per 1,000 person-years; HR, 0.93; 95% CI, 0.80–1.09; P = 0.39), total stroke (4.1 and 3.9 events per 1,000 person-years; HR, 1.06; 95% CI, 0.91–1.23; P = 0.48), or CVD mortality (5.0 and 5.1 events per 1,000 person-years; HR, 0.95; 95% CI, 0.83–1.09; P = 0.47). A daily multivitamin also was not significantly associated with total mortality (HR, 0.94; 95% CI, 0.88–1.02; P = 0.13).

In contrast, men taking a daily multivitamin had a significant reduction in the incidence of total cancer (multivitamin and placebo groups, 17.0 and 18.3 events, respectively, per 1,000 person-years; HR, 0.92; 95% CI, 0.86–0.998; P = 0.04). There was no significant effect of daily multivitamin use on prostate cancer (multivitamin and placebo groups, 9.1 and 9.2 events, respectively, per 1,000 person-years; HR, 0.98; 95% CI, 0.88–1.09; P = 0.76), colorectal cancer (multivitamin and placebo groups, 1.2 and 1.4 events, respectively, per 1,000 person-years; HR, 0.89; 95% CI, 0.68–1.17; P = 0.39), or other site-specific cancers. There also was no significant difference in the risk of cancer mortality (multivitamin and placebo groups, 4.9 and 5.6 events, respectively, per 1,000 person-years; HR, 0.88; 95% CI, 0.77–1.01; P = 0.07).

JAMA. 2012;308:1751-60.
JAMA. 2012;308:1871-80.