Since the passage of the Dietary Supplements Health and Education Act (DSHEA) in 1994, U.S. sales of dietary supplements (DS) – defined by the legislation as products intended to supplement the diet, including vitamins, minerals, herbs and botanicals, amino acids, and substances such as enzymes, organ tissues, glandulars, and metabolites  – have risen dramatically from $8.8 billion  to an estimated $28.7 billion for 2010 . There has also been a substantial increase in the proportion of adults, both civilian and military, who regularly use DS – current estimates suggest that 52% of U.S. adults and 53% of military personnel regularly use some form of DS [4, 5].
Dietary supplements are commonly consumed by Americans to promote general health, improve energy or memory, and to treat or prevent medical conditions such as osteoporosis or arthritis . However, for a majority of supplements, there is limited evidence to support such benefits. Consumers may also believe that DS are “natural” remedies, and are, therefore, safer to consume than traditional medical treatments, such as drugs . However, U.S. federal regulations do not subject DS to the same stringent safety and efficacy regulations that the Food and Drug Administration (FDA) imposes on prescription and over-the-counter drugs .
Although manufacturers are legally responsible for ensuring the safety of DS and for ensuring any product claims are not false or misleading , they are not required to provide definitive pre-market substantiation of either safety or efficacy, or to have the product evaluated by an independent scientific regulatory entity. Rather, the onus for determining if or whether a DS is unsafe is on the FDA; for the agency to recall a supplement, it must obtain sufficient evidence that the specific supplement in question is unsafe and poses a “significant or unreasonable risk of illness or injury” [8, 9]. Manufacturers must inform the FDA prior to introducing a new dietary ingredient to the market. However this notification is often not accompanied by a safety assessment of the product . Statements and claims suggesting possible benefits of consuming a DS are also minimally regulated. Manufacturers may make “structure-function claims” on packaging, provided claims do not reference a specific disease or condition, and provided their claims are qualified with the disclaimer, “This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease”.
Industry data indicate that consumer confidence in the safety, quality and effectiveness of DS has increased over the past decade. In 2001, 74% of American adults surveyed indicated they were somewhat or very confident in the safety, quality and effectiveness of dietary supplements. By 2010, that number had increased to 82% [11, 12]. This high level of confidence may be due to consumers’ misconceptions about the extent of pre-market review and regulatory oversight that a DS must undergo. Many Americans are unaware or misinformed about the FDA’s role in regulating DS [7, 9, 13, 14], and may assume that DS are subject to the same efficacy and safety testing as OTC drugs . Such beliefs may foster a false sense of security in the efficacy and safety of supplements. In fact, making individuals explicitly aware that the FDA had not approved a particular DS made them more skeptical of the product’s safety, although it did not affect participants’ ratings of product efficacy . This may suggest consumers are willing to rely on their own experiences to form opinions regarding DS efficacy, but are less likely to rely on their own experiences to form opinions regarding DS safety.
While there is an increasing body of literature examining characteristics of supplement users, relatively little is known about the factors that influence consumer confidence in DS. However, regular users of DS are more inclined to believe supplements are effective and safe compared to non-users [2, 9, 16, 17]. The purpose of this study was to assess beliefs about DS efficacy and safety among U.S. Army Active Duty personnel, a population known to have a high frequency of DS use , and to investigate whether certain demographic and lifestyle factors of DS users are associated with higher confidence in either attribute. We hypothesized that confidence in DS efficacy and safety would be associated with age, education, and self-reported fitness level because similar factors were associated with DS use among military personnel in a previous investigation . Additionally, we evaluated whether knowledge of the government’s role in DS regulation influenced users’ beliefs that DS work and are safe to consume.