Supplement use among cancer survivors in the Vitamins and Lifestyle (VITAL) study cohort.

OBJECTIVES

Although dietary supplement use is believed to be prevalent among patients with cancer, less is known about specific associations of supplements with types of cancer. These analyses describe the use of specific supplements by 10,857 cancer survivors in comparison to cancer-free controls (n = 64,226).

DESIGN

Cross-sectional cohort study. SUBJECTS/SETTINGS/LOCATION: Participants were members of the VITAL (Vitamins and Lifestyle) study, a cohort study of 75,288 men and women in western Washington State, 50-76 years of age, examining supplement use and future cancer risk. INTERVENTIONS/OUTCOME MEASURES: Respondents completed a 24-page questionnaire, including information on cancer history, demographic characteristics, and current use of vitamin, mineral, and herbal supplements.

RESULTS

In this cohort, cancer survivors used similar numbers of supplements as cancer-free controls. Analyses examined the association of a diagnosis history of 11 specific cancers (n > or = 280), by anatomic site, with the high use of multivitamins and 16 individual vitamin/mineral and 20 herbal/specialty supplements. In analyses adjusted for gender, age, education, and race/ethnicity, odds ratios and 95% confidence intervals for the strongest positive associations were: cranberry pills with bladder cancer 3.44 (1.86, 6.35); zinc with ovarian cancer 2.19 (1.41, 3.40); soy with prostate cancer 1.99 (1.38, 2.87); melatonin with cervical cancer 1.86 (1.19, 2.90); and vitamin D with thyroid cancer 1.66 (1.21, 2.28).

CONCLUSIONS

Future research needs to assess the efficacy and safety of these specific supplements in these specific cancer populations.