Vitamin and mineral supplements are among the most commonly used drugs in the United States, despite limited evidence on their benefits or risks. This paper describes the design, implementation, and participant characteristics of the VITamins And Lifestyle (VITAL) Study, a cohort study of the associations of supplement use with cancer risk. A total of 77,738 men and women in western Washington State, aged 50-76 years, entered the study in 2000-2002 by completing a detailed questionnaire on supplement use, diet, and other cancer risk factors, and 70% provided DNA through self-collected buccal cell specimens. Supplement users were targeted in recruitment: 66% used multivitamins, 46% used individual vitamin C, 47% used individual vitamin E, and 46% used calcium, typically for 5-8 of the past 10 years. Analyses to identify confounding factors, the main study limitation, showed that regular nonsteroidal anti-inflammatory drug use, intake of fruits and vegetables, and recreational physical activity were strongly associated with supplement use (p < 0.001). The authors describe a follow-up system in which cancers, deaths, and changes of residence are tracked efficiently, primarily through linkage to public databases. These methods may be useful to other researchers implementing a large cohort study or designing a passive follow-up system.

In the United States, dietary supplements contribute a large proportion of micronutrient intakes. Therefore, it is important to collect accurate information on supplement use for studies of micronutrients and disease risk. This report describes the test-retest reliability and validity of a detailed, self-administered mailed questionnaire on vitamin and mineral supplement use. Participants (n = 220) completed the questionnaire at baseline and 3 months later. During an in-person interview, participants provided spot urine and blood samples, and interviewers transcribed nutrient information from their supplement bottle labels. The questionnaire had very good test-retest reliability for mean supplement intake over the past 10 years, with intraclass correlations ranging from 0.69 for beta-carotene to 0.87 for vitamin E. Pearson's correlation coefficients comparing current supplemental intakes from the questionnaire and interviews/label transcriptions were high, ranging from 0.58 for beta-carotene to 0.82 for chromium; however, for some nutrients, median intakes from the questionnaire were slightly lower than from the interviews. Beta-carotene, vitamin C, and vitamin E (alpha-tocopherol) showed clear linear trends of increasing blood concentrations with higher self-reported supplemental intakes (Pearson's correlation coefficients adjusted for potential confounding factors and diet = 0.31, 0.29, and 0.69, respectively; all p < 0.0001). Creatinine-adjusted spot urinary calcium values were not associated with supplemental calcium intakes (Pearson's r = -0.07). This self-administered questionnaire demonstrated high reproducibility and validity for collecting detailed information on supplement use.

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Objective: This report examines how sources of fat and patterns of fat-related dietary habits differed between black, Hispanic and white women participating in a randomized trial of a low-fat diet intervention. Design: The intervention consisted of group sessions, which met weekly for 6 weeks, biweekly for 6 weeks and monthly for 9 months, and included didactic nutrition education and activities to provide motivation for sustained dietary change. Outcomes included total fat and fat from nine food groups from a food frequency questionnaire (FFQ), and a summary scale and five subscales that measure fat-related dietary habits. Setting/subjects: Data are from 1702 post-menopausal women, recruited from clinical centres in Atlanta, Birmingham and Miami, with dietary assessments at baseline and 6 months post-randomization. Results: Total fat intake was similar across race/ethnic groups at baseline, yet there were many differences in sources of fat and fat-related dietary habits. For example, blacks consumed less fat from dairy foods and more fat from meats than whites. Effects of the intervention on total fat intake or the summary fatrelated dietary habits scale did not differ across race/ethnicity groups. There were, however, many differences in how the intervention affected sources of fat and fatrelated dietary habits. For example, the intervention effect for added fats (e.g. butter and salad dressings) was −8.9 g for blacks and −12.0 g for whites (P Ͻ 0.05). The intervention effect for adopting low-fat meat purchasing and preparation methods was larger for blacks than whites, and the intervention effect for replacing high-fat foods with fruits and vegetables was larger for Hispanics than whites. Conclusions: This study demonstrates that, if properly designed, a single nutrition intervention programme can work well even in groups with culturally diverse dietary patterns.

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We developed a new dietary assessment instrument, the Food Behavior Checklist (FBC), which measures food use related to adopting lower-fat and higher-fiber diets. The FBC is a simplification of the 24-hour diet recall that consists of 19 simple yes/no questions about foods consumed during the previous day. To develop the FBC, an expert committee generated a list offoods based on our intervention program, and we used focus groups and randomdigit dialing pretests to refine the format and clarify items. To validate the FBC, we compared responses of 96 women on the FBC to information collected during a professionally administered 24-hour diet recall. For most items, agreement between the FBC and 24-hour recall, based on the kappa statistic, was good to excellent. Agree- IntroductionThere

These data suggest that long-term users of certain supplements experienced less weight gain than individuals who did not use the supplements. Further study is necessary before recommendations regarding these supplements can be made.

Our results suggest that a dietary intervention aimed at women can have an effect on their husbands and may be a cost-effective approach to healthy dietary change for both women and men.