title: Vitamin/mineral supplementation and cancer, cardiovascular, and all-cause mortality in a German prospective cohort (EPIC-Heidelberg).
abstract: OBJECTIVE
  To prospectively evaluate the association of vitamin/mineral supplementation with cancer, cardiovascular, and all-cause mortality.
  
  
  METHODS
  In the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Heidelberg), which was recruited in 1994-1998, 23,943 participants without pre-existing cancer and myocardial infarction/stroke at baseline were included in the analyses. Vitamin/mineral supplementation was assessed at baseline and during follow-up. Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).
  
  
  RESULTS
  After an average follow-up time of 11 years, 1,101 deaths were documented (cancer deaths = 513 and cardiovascular deaths = 264). After adjustment for potential confounders, neither any vitamin/mineral supplementation nor multivitamin supplementation at baseline was statistically significantly associated with cancer, cardiovascular, or all-cause mortality. However, baseline users of antioxidant vitamin supplements had a significantly reduced risk of cancer mortality (HR: 0.52; 95% CI: 0.28, 0.97) and all-cause mortality (HR: 0.58; 95% CI: 0.38, 0.88). In comparison with never users, baseline non-users who started taking vitamin/mineral supplements during follow-up had significantly increased risks of cancer mortality (HR: 1.74; 95% CI: 1.09, 2.77) and all-cause mortality (HR: 1.58; 95% CI: 1.17, 2.14).
  
  
  CONCLUSIONS
  Based on limited numbers of users and cases, this cohort study suggests that supplementation of antioxidant vitamins might possibly reduce cancer and all-cause mortality. The significantly increased risks of cancer and all-cause mortality among baseline non-users who started taking supplements during follow-up may suggest a "sick-user effect," which researchers should be cautious of in future observational studies.
authors.affiliation: Division of Cancer Epidemiology, German Cancer Research Centre, Heidelberg, Germany.
authors.forename: Kuanrong
authors.initials: K
authors.lastname: Li
authors.forename: Rudolf
authors.initials: R
authors.lastname: Kaaks
authors.forename: Jakob
authors.initials: J
authors.lastname: Linseisen
authors.forename: Sabine
authors.initials: S
authors.lastname: Rohrmann
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000009:adverse effects / Q000627:therapeutic use; D002318:Cardiovascular Diseases / Q000178:diet therapy / Q000401:mortality / Q000517:prevention & control*; D015331:Cohort Studies; D019587:Dietary Supplements / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008903:Minerals / Q000009:adverse effects / Q000627:therapeutic use*; D009026:Mortality; D009369:Neoplasms / Q000178:diet therapy / Q000401:mortality / Q000517:prevention & control*; D009749:Nutrition Surveys; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012306:Risk; D014504:Urban Health; D014815:Vitamins / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D000975:Antioxidants; D008903:Minerals; D014815:Vitamins