Prevalence and Correlates of Vitamin and Supplement Usage Among Men With a Family History of Prostate Cancer

Abstract

Hypotheses. Men who have a brother with prostate cancer have a 2-fold increased risk of being diagnosed with prostate cancer. Strategies employed by these men to reduce prostate cancer risk are not well understood. Preliminary studies have shown that men with a family history of prostate cancer have a high rate of vitamin and supplement usage aimed at the prevention of prostate cancer. Study design. The authors analyzed data from a cross-sectional study of men with familial and hereditary prostate cancer and their unaffected brothers. A total of 542 unaffected men who had at least one brother who had been diagnosed with prostate cancer regarding their use of vitamins and supplements, as well as the motivation for use, were interviewed. Methods. The associations between subject characteristics and vitamin and supplement use were evaluated using an unconditional logistic regression modeling approach. Results. Overall, 59.2% and 36.5% of men reported ever using and currently using, respectively, one or more vitamins or supplements (including multivitamins). One third of men took a vitamin or supplement that has been targeted for prostate health or cancer prevention, including green tea, magnesium, male hormones, saw palmetto, selenium, soy, vitamins A, C, E, and zinc. Increasing age at time of survey was associated with vitamin/supplement use (odds ratio [OR] = 1.03; 95% confidence interval [CI] = 1.01-1.05). After adjusting for age at time of survey, being younger than an affected brother was associated with vitamin and supplement use (OR = 1.51; 95% CI = 1.01-2.25). A total of 25% of men reported obtaining information from books or articles as the most common source of information. Conclusions. The findings indicate that men at an increased risk for prostate cancer report a high rate of vitamin and supplement use, including supplements targeted for prostate cancer prevention. Men with a family history of prostate cancer represent a target population for future chemopreventative agents.