VITAL Vitamins and Lifestyle Study: Cohort Study of Dietary Supplements and Cancer Risk

Emily White, Ph.D.
University of Washington, Fred Hutchinson Cancer Research Center
Cancer Prevention Research Program, Seattle, Wash.
Funded since 1999
Web site

Vitamin and mineral supplements are among the most commonly used drugs in the United States. Manufacturers market and consumers use supplements to prevent chronic diseases such as cancer, but with the exception of beta-carotene, there is sparse evidence for either their benefits or risks. The overall aim of this research is to investigate the associations of supplement use with cancer risk. Specific aims focus on the associations of vitamin C, vitamin E, calcium and multivitamins with prostate, female breast, lung, colorectal, and total cancer incidence.

In the initial 5 years of this cohort study, 77,700 men and women, aged 50 to 76 and living in a 13-county area of western Washington State were recruited into the cohort. Cohort members completed a baseline questionnaire covering detailed information on supplement use over the past 10 years, diet (using a food frequency questionnaire), health history, and cancer risk factors. Seventy percent of participants provided DNA by self-collected buccal brushes.

Supplement users were targeted in recruitment, therefore supplement use by cohort members is both high and of long duration. Cancer endpoint information is ascertained by linkage to the western Washington (Seattle-Puget Sound) cancer registry, which is part of the NCI-funded Surveillance, Epidemiology, and End Results (SEER) Program, and deaths by linkage to the Washington State death file. Out-migration from the SEER catchment area is monitored by linkage to the National Change of Address file. If the study continues for an additional 5 years, approximately 6,000 cancers are expected to be diagnosed, allowing completion of the analyses to address the specific aims.

If supplements are harmful or of no use in relation to cancer, this information is important for the large number of Americans taking supplements. If beneficial effects are found, these could be translated into highly cost-effective cancer control measures.