VITamins And Lifestyle Cohort Study: Study Design and Characteristics of Supplement Users

• Published in: American journal of epidemiology Vol. 159; no. 1; pp. 83 - 93
• Main Authors: White, Emily, Patterson, Ruth E., Kristal, Alan R., Thornquist, Mark, King, Irena, Shattuck, Ann L., Evans, Ilonka, Satia-Abouta, Jessie, Littman, Alyson J., Potter, John D.
• Format: Journal Article
• Language: English
• Published: Cary, NC Oxford University Press 01.01.2004; Oxford Publishing Limited (England)
• Subjects: Aged; Analysis. Health state; and End Results; Biological and medical sciences; calcium; Cancer; Cohort Studies; data collection; Dietary Supplements; epidemiologic research design; Epidemiology; Female; Follow-Up Studies; General aspects; Health risk assessment; Humans; Life Style; Lifestyles; Male; Medical sciences; Middle Aged; Minerals; Neoplasms - epidemiology; Neoplasms - etiology; Neoplasms - prevention & control; Public health. Hygiene; Public health. Hygiene-occupational medicine; Research Design; SEER; SEER Program; Surveillance; Surveys and Questionnaires; VITAL; Vitamins; Vitamins - administration & dosage; VITamins And Lifestyle; Washington - epidemiology; Washington; Human; Statistical analysis; Calcium; Health; Vitamin; Inorganic element; Epidemiology; data collection; follow-up studies; vitamins; Characteristics; Follow up study; Cohort study; dietary supplements; Supplementation; Public health; Life style; epidemiologic research design
• ISSN: 0002-9262; 1476-6256; 0002-9262
• DOI: 10.1093/aje/kwh010

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.