Passage of the Dietary Supplement and Health Education Act (DSHEA) in 1994 stimulated growth of the dietary supplement industry. Knowledge about the industry, DSHEA, and what drives consumer sales helps provide insight into what makes the dietary supplement industry unique. When DSHEA was passed (1994), sales of dietary supplements were about $4 billion; today, they are $21 billion.1,2 Although the overall growth figure is impressive, not all segments of the industry have enjoyed or sustained these numbers. Over 90% of the industry is classified as small businesses, that is, revenues under $20 million. The number of companies with revenues that exceed $100 million is relatively small, and only a handful have revenues that exceed $1 billion.2,3 These figures are achieved through sale of a wide range of products (brands). By contrast, pharmaceutical industry annual sales in the United States are over $200 billion, and a blockbuster single brand is one that has annual sales that exceed a billion. The pharmaceutical industry is also less prone to dramatic swings in sales, like the dietary supplement industry. These facts are relevant in terms of the dollars (percentage cost of goods sold) that dietary supplement companies can allocate for research to support the safety, quality, and efficacy of brands. There is the expectation by some in the health professional community for dietary supplement companies to meet similar standards as pharmaceutical products. If this is to happen, some other funding sources to support research must be provided through public and private organizations.
Dietary supplements are regulated as foods. They are available for sale in traditional food outlets and other venues. However, traditional food outlets account for less than 30% of consumer sales (see Table 1). Furthermore, sales through these food outlets declined by 1.5% in 2005. On the other hand, sales through the other outlets (eg, natural and specialty stores and multilevel marketing) grew by more than 5% in 2005. For example, sales through natural and specialty retail outlets rose by 6.2% and accounted for 36% of consumer sales.2 This trend is likely to continue because of the rapid overall growth of natural and specialty retail outlets (eg, Whole Foods and Wild Oats), and higher profit margins of products sold through these outlets, making them more attractive than the traditional food outlets.
The industry has changed in the 10 years post-DSHEA. When DSHEA was enacted, there were about 4,000 dietary supplement products on the market. By 1999, this number had grown to 29,000 products (a current figure is not available).3-5 There have been several unsuccessful attempts at consolidating the industry. For example, the major pharmaceutical companies sought to grow their over-the-counter divisions through brand acquisition or alliances between 1999 and 2003, but these consolidations failed. Thus, the industry remains very fragmented, with a wide range of companies functioning under different operating philosophies. This is one reason why it is difficult to achieve agreement within the dietary supplement industry on regulatory and scientific principles to self-regulate the industry.
When President Clinton signed DSHEA into law in October 1994, dietary supplements became a separate regulatory category for the first time.6,7 The DSHEA authorized the Food and Drug Administration (FDA) to regulate supplements as a subset of foods and prohibited their regulation as drugs or food additives. Dietary supplements can be sold in food form (eg, bars and beverages) as long as they are not represented for use as a conventional food or as the sole item of a meal or diet and they are labeled as "dietary supplement." The DSHEA made substantial changes that affected the supplement industry, consumers, and health professionals. It provided (a) a legal definition of "dietary supplement" and "new dietary ingredients"; (b) a framework for addressing safety that placed the burden of proof on the FDA; (c) guidance on the appropriate use of statements of "nutritional support" (referred to as structure/function claims) that do not require premarket approval; (d) ingredient and nutrition information and other labeling standards; (e) a premarket notification procedure for new dietary ingredients; and (f) the FDA the authority to establish Good Manufacturing Practices for dietary supplements. However, it did not provide appropriations sufficient to enable the FDA to carry out all the functions outlined in DSHEA.
Although the FDA has made an effort to implement some provisions of the DSHEA, budget constraints have limited its ability to adequately implement and enforce regulations. As a result, the quality of some products is questionable. Consumers cannot tell which products available in the marketplace meet label claims. To meet this need, a number of third-party quality assurance programs have been developed to help build consumer confidence in the quality of dietary supplements. However, these are voluntary programs that offer seals of approval to companies that participate (for a fee) and meet the criteria established by the program.
A variety of factors, such as recommendations from family and friends, advertisements, and health professional advice, contribute to consumer demand for dietary supplements. As noted in Elizabeth Sloan's article (in this issue), 12% of consumers took a vitamin and mineral supplement on the recommendation of their physician. But no one factor affects sales more than positive and negative media reports. St John's wort is a historic example. Consumer demand for St John's wort surged because of a 1997 ABC News 20/20 report ("Using herb St. John's wort to treat depression").4 In Germany, St John's wort is the leading treatment for depression. Negative media coverage between 1998 and 2003 on the failure of St John's wort products to meet label claims, interactions with prescription drugs, and findings from a clinical trail that demonstrated a lack of effectiveness in the treatment of major depression stifled sales (note: this product is intended for use in the short-term management of minor depression). In 1998, St John's wort sales were $400 million, sales were up almost 4000% in 2004, sales were $59 million. A more recent example of media hype is resveratrol. In a study published November 2006 and supported by the National Institutes of Health, overweight aged male mice fed a high-calorie (fat) diet supplemented with resveratrol (24 mg/kg of body weight) had better health and survival than mice who did not receive it. The study did not include information on findings in humans. Nevertheless, the study received extensive media coverage and resulted in a jump in consumer sales. Even though, to quote from a Wall Street Journal editorial, "the tested mice were stuffed with more resveratrol than even the most ardent oenophile could consume," many retail stores were unable to maintain stock of resveratrol products in November 2006.
It is difficult to predict how the industry will evolve in the next 10 years. However, we know that it is constantly evolving. Whether it expands or declines will depend on evidence that products are safe and effective, and meet label claims. Nutritionists and health professionals need to be up-to-date on the evidence base for these products. (Table 2 provides a list of useful resources for professionals.) As individuals continue to take greater responsibility of their healthcare, the demand for self-care products such as dietary supplements will continue.
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