Dietary supplements are used by half to two-thirds of American adults, and the evidence suggests that this usage is one component of a larger effort to develop a healthier lifestyle. Dietary supplement users tend on average to be better educated and to have somewhat higher incomes than nonusers, and these factors may contribute to their health-consciousness. Dietary supplement use also tends to be more prevalent among women than among men, and the prevalence of use increases with age in both men and women. Numerous surveys document that users of dietary supplements are significantly more likely than nonusers to have somewhat better dietary patterns, exercise regularly, maintain a healthy weight, and avoid tobacco products. While supplement users tend to have better diets than nonusers, the differences are relatively small, their diets have some substantial nutrient shortfalls, and their supplement use has been shown to improve the adequacy of nutrient intakes. Overall, the evidence suggests that users of dietary supplements are seeking wellness and are consciously adopting a variety of lifestyle habits that they consider to contribute to healthy living.