do so moderately, but there are also a very high proportion of abstainers. Supplement users report that they do regular cancer screening tests and they tend to be healthier.

Another group frequently thought of as supplement-takers are athletes and exercisers. Indeed, Gregor’s review of recent surveys does bear that finding. Seventy-five percent of marathoners, for instance, take two or more dietary supplements.

Lastly, there is a persistent impression that people who are in poor health are more likely to take dietary supplements than people who are in good health. A review of these surveys shows inconsistent information. Some studies report that people who have one or more health problems are more likely to take dietary supplements; others show that people with diagnosed hypertension, cancer, and cardiovascular disease do not take more dietary supplements than those who are not diagnosed. The question is still open as to whether people who are in ill health are more likely to take dietary supplements than those who are not.

Who makes these supplements? There are about 1,000 different companies listed by the Nutrition Business Journal as makers of supplements (Table 3). The vast majority are small to mid-sized companies that assemble ingredients purchased from raw material suppliers, of which there are approximately 40 in this country. Of the 40 suppliers, eight are large pharmaceutical companies that supply over 75 percent of the vitamins that are incorporated into formulations made by the smaller companies. There are about 150 suppliers of herbal and botanical raw materials.

How are the supplements marketed? The major outlets include the natural and health food chain stores, accounting for about 35 percent of the market share. They are followed by the mass merchandisers, grocery stores, and drug stores. Increasingly, grocery stores have major sections devoted to dietary supplements. The next group of vendors are multilevel marketing firms. These are direct sales companies, marketing through home parties or in door-to-door sales. Direct mail order only accounts for about six percent of the market. Surprisingly, health care