摘要：Millions of people in the United States consume dietary supplements hoping to maintain or improve their health; however, extensive research has failed to demonstrate the efficacy of numerous supplements in disease prevention. In addition, concerns about the safety of routine and high-dose supplementation have been raised. The Food and Drug Administration regulates dietary supplement quality, safety, and labeling, and the Federal Trade Commission monitors advertisements and marketing; still, vast enforcement challenges remain, and optimal governmental oversight has not been achieved. If the composition and quality of ingredients cannot be reliably ensured, the validity of research on dietary supplements is questionable. Moreover, the health of the US public is put at risk. The number of dietary supplements (see the box on the next page 1 ) sold in the United States has dramatically increased since the passage of the Dietary Supplement Health and Education Act (DSHEA), from about 4000 when law went into effect in 1994 to more than 90 000 in 2014. 2,3 Approximately 150 million persons in the United States use dietary supplements, with 79% reporting daily use and 10% taking 5 or more per day. 4,5 Botanical dietary supplements are used by 17.9% of US adults. 6 Persons in the United States report using dietary supplements to maintain or improve overall health and the health of specific organs, prevent disease, increase energy, improve mental health, achieve weight loss, and resolve miscellaneous health issues such as menopause and hot flashes. 7,8 Only 22% reported using them to supplement their diet. 7 Almost 23 million US persons report using dietary supplements instead of drugs, and 30 million use them instead of over-the-counter medications. 9 US Federal Government Definition of Dietary Supplements According to the Dietary Supplement Health and Education Act of 1994, dietary supplements include a large heterogeneous group of products intended to supplement the diet that are not better described as drugs, foods, or food additives. Supplements may contain, in whole or as a concentrate, metabolite, constituent, or extract, any combination of 1 or more vitamins, minerals, amino acids, herbs or other botanicals, and other substances used to increase total dietary intake, including enzymes, organ tissues, and oils. They must be intended for ingestion; sold in the form of capsules, tablets, soft gels, gel caps, powders, or liquids; and not be marketed as food items. Open in a separate window Source. Dietary Supplement Health and Education Act of 1994. 1 Dietary supplement use has grown despite insufficient evidence to demonstrate clear health benefits for most and concerns of increased health risks for several. 7,10–14 Nine in 10 health food stores suggest dietary supplements for treating a variety of illnesses, from hypertension to cancer. 15–19 Limited evidence of efficacy exists for some dietary supplements; however, serious safety issues and drug supplement interactions have been documented. 20–22 One study has estimated that at least 1 in 12 US adults takes botanical dietary supplements known to cause kidney damage; other dietary supplements are known carcinogens, hepatotoxins, hormone modulators, and sympathomimetics. 23,24 Dietary supplements may be adulterated with dangerous compounds, be contaminated, fail to contain the purported active ingredient, or contain unknown doses of the ingredients stated on the label; be sold at toxic dosages; or produce harmful effects as a result of their interaction with other drugs. 9,25 Additional safety issues may arise from megadosing, which three quarters of persons in the United States believe can produce greater health benefits than taking the daily recommended value. 26 For several vitamins and minerals, a U-shaped relationship between supplement dosing and mortality has been observed, indicative of substantial toxicity with high-dose supplementation. 27–29 As many as a third of calls to poison control centers associated with dietary supplements report such adverse events (AEs) as coma, seizure, myocardial infarction, liver failure, and death. 30 Despite extensive research on dietary supplements, little attention in public health has focused on challenges in their regulation. The regulatory aspects of the dietary supplement industry provide context for several areas of public health interest, including consumer behavior with respect to use, safety, and efficacy and research focused on health effects of routine supplementation.
