Use of dietary supplements is widespread, yet intakes from supplements are difficult to quantify. The Supplement Reporting study utilized a unique inventory method to quantify dietary supplement use across 1 year in a sample of 397 supplement users. Interviewers visited participants' homes in 2005-2006 to record supplement purchases and the number of pills in each supplement bottle every 3 months. Total use for the year was calculated from these inventories. Participants in this observational study were older adults (average age 68 years) from the Multiethnic Cohort in Hawaii and Los Angeles, CA, with approximately equal representation of men and women and six ethnic groups (white, Japanese American, Hawaiian, African American, Latinos born in the United States, and Latinos born elsewhere).
