Use of multivitamins and prostate cancer mortality in a large cohort of US men.

OBJECTIVE

To assess the association between the use of multivitamins and prostate cancer mortality.

METHODS

A total of 5585 deaths from prostate cancer were identified during 18 years of follow-up of 475,726 men who were cancer-free and provided complete information on multivitamin use at enrollment in the Cancer Prevention Study II (CPS-II) cohort in 1982. Cox proportional hazards modeling was used to measure the association between multivitamin use at baseline and death from prostate cancer and to adjust for potential confounders.

RESULTS

The death rate from prostate cancer was marginally higher among men who took multivitamins regularly (> or =15 times/month) compared to non-users (multivariate rate ratio=1.07, 95% CI: 0.99-1.15); this risk was statistically significant only for those multivitamin users who used no additional (vitamin A, C, or E) supplements (multivariate rate ratio=1.15, 95% CI: 1.05-1.26). In addition, risk was greatest during the initial four years of follow-up (1982-1986, multivariate rate ratio=1.12, 95 CI: 0.87-1.46).

CONCLUSIONS

Regular multivitamin use was associated with a small increase in prostate cancer death rates in our study, and this association was limited to a subgroup of users.