title: Multivitamins in the prevention of cancer in men: the Physicians' Health Study II randomized controlled trial.
abstract: BACKGROUND
  Multivitamin preparations are the most common dietary supplement, taken by at least one-third of all US adults. Observational studies have not provided evidence regarding associations of multivitamin use with total and site-specific cancer incidence or mortality.
  
  
  OBJECTIVE
  To determine whether long-term multivitamin supplementation decreases the risk of total and site-specific cancer events among men.
  
  
  METHODS
  A large-scale, randomized, double-blind, placebo controlled trial (Physicians" Health Study II) of 14 641 male US physicians initially aged 50 years or older (mean [SD] age, 64.3 [9.2] years), including 1312 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.
  
  
  METHODS
  Daily multivitamin or placebo.
  
  
  METHODS
  Total cancer (excluding nonmelanoma 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 2669 men with confirmed cancer, including 1373 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 1000 person-years; hazard ratio [HR], 0.92; 95% CI, 0.86-0.998; P=.04). There was no significant effect of a daily multivitamin on prostate cancer (multivitamin and placebo groups, 9.1 and 9.2 events, respectively, per 1000 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 1000 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 1000 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 1312 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). Conclusion In this large prevention trial of male physicians, daily multivitamin supplementation modestly but significantly reduced the risk of total cancer.
  
  
  BACKGROUND
  clinicaltrials.gov Identifier: NCT00270647.
authors.affiliation: Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts 02120, USA. jmgaziano@partners.org
authors.forename: J Michael
authors.initials: JM
authors.lastname: Gaziano
authors.forename: Howard D
authors.initials: HD
authors.lastname: Sesso
authors.forename: William G
authors.initials: WG
authors.lastname: Christen
authors.forename: Vadim
authors.initials: V
authors.lastname: Bubes
authors.forename: Joanne P
authors.initials: JP
authors.lastname: Smith
authors.forename: Jean
authors.initials: J
authors.lastname: MacFadyen
authors.forename: Miriam
authors.initials: M
authors.lastname: Schvartz
authors.forename: JoAnn E
authors.initials: JE
authors.lastname: Manson
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Glynn
authors.forename: Julie E
authors.initials: JE
authors.lastname: Buring
mesh_terms: D000368:Aged; D019587:Dietary Supplements; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D010820:Physicians; D012306:Risk; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D014815:Vitamins