National surveys, such as the Third National Health and Nutrition Examination Survey (1988–1994) and the 1987 and 1992 National Health Interview Surveys, indicate that 40 to 46 percent of Americans reported taking at least one vitamin or mineral supplement at some time within the month surveyed (Balluz et al., 2000; Slesinski et al., 1995). However, data from national surveys collected before the enactment of DSHEA in 1994 may not reflect current supplement consumption patterns (Costello and Grumpstrup-Scott, 2000), and there are limitations to interpreting user characteristics from sales data (Radimer et al., 2000). Several studies have also explored the prevalence of nutrient supplement (thought to be primarily vitamin and mineral formulations) use and trends in the United States (Balluz et al., 2000; Bender et al., 1992; Kim et al., 1993; Koplan et al., 1986; Slesinski et al., 1995; Subar and Block, 1990), as well as users’ motivation for taking vitamin and mineral supplements (Neuhouser et al., 1999) and characteristics of users versus nonusers (Dwyer et al., 2001; Ford, 2001; Hartz et al., 1988; Lyle et al., 1998; Nayga and Reed, 1999; Pelletier and Kendall, 1997; Subar and Block, 1990). However, knowledge about the use prevalence and trends of dietary supplements (which include nonvitamin, nonmineral supplements) is limited (Radimer et al., 2000).

Results from a more recent national survey of 2,000 adults indicated that 85 percent of respondents had used one or more dietary supplements in the previous 12 months (Prevention Magazine, 2001). If this sample of U.S. consumers was representative of the total population, it would translate into more than 44 million consumers using botanical remedies and an estimated 24 million using specialty supplements (e.g., bee pollen, dehydroepiandrosterone, chondroitin sulfate, kava kava, shark cartilage, and Sadenosylmethionine) (Prevention Magazine, 2001; Radimer et al., 2000; Ramos, 2000).

Existing studies of reported dietary supplement use suggest an association between increased use of dietary supplements by older individuals and those who report having more healthful lifestyles (Radimer et al., 2000). The most frequent reason given for dietary supplement use in one national survey was desire for self-care (Prevention Magazine, 2001). Some consumers report using supplements because of a belief that these products will ensure good health. Generally, labeling for a dietary supplement may not claim to “diagnose, mitigate, treat, cure, or prevent a specific disease or class of diseases” (DSHEA, P.L. 103-417, § 6 [1994]; (FDCA), 21 U.S.C. § 343(r)(6)(C) [2001]). Nonetheless, consumers have reported using supplements for purposes such as to treat and prevent illnesses, colds, and flu and to alleviate depression (Prevention Magazine, 2001). There is also a re-