Nutraceutical: Multivitamins

Indication: Cancer among men

Source: JAMA 2012;308(18):1871-1880

Research: Multivitamin preparations are the most common dietary supplement, taken by at least one-third of all U.S. adults. This study aimed to determine if long-term multivitamin supplementation decreases the risk of total and site-specific cancer events among men. A large-scale, randomized, double-blind, placebo-controlled trial (Physicians’ Health Study II) of 14,641 male U.S. physicians initially aged 50 years or older (mean [SD] age, 64.3 [9.2] years), including 1,312 men with a history of cancer at randomization, enrolled in a common multivitamin study that began in 1997 with treatment and follow-up through June 1, 2011. Subjects received a daily multivitamin or placebo. Main outcome measures included total cancer (excluding non-melanoma skin cancer), with prostate, colorectal and other site-specific cancers among the secondary end points.

Results: During a median (interquartile range) follow-up of 11.2 (10.7-13.3) years, there were 2,669 men with confirmed cancer, including 1,373 cases of prostate cancer and 210 cases of colorectal cancer. Compared with placebo, men taking a daily multivitamin had a statistically significant reduction in the incidence of total cancer (multivitamin and placebo groups, 17.0 and 18.3 events, respectively, per 1,000 person-years; hazard ratio [HR], 0.92; 95% CI, 0.86-0.998; P = .04). According to results, there was no significant effect of a daily multivitamin 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 = .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 = .39), or other site-specific cancers. There 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 = .07). Daily multivitamin use was associated with a reduction in total cancer among 1,312 men with a baseline history of cancer (HR, 0.73; 95% CI, 0.56-0.96; P = .02), but this did not differ significantly from that among 13,329 men initially without cancer (HR, 0.94; 95% CI, 0.87-1.02; P = .15; P for interaction = .07). Researchers concluded that in this large prevention trial of male physicians, daily multivitamin supplementation modestly but significantly reduced the risk of total cancer.