A dietary supplement, also known as food supplement or nutritional supplement, is a preparation intended to provide nutrients, such as vitamins, minerals, fiber, fatty acids or amino acids, that are missing or are not consumed in sufficient quantity in a person's diet. Some countries define dietary supplements as foods, while in others they are defined as drugs.
Supplements containing vitamins or dietary minerals are included as a category of food in the Codex Alimentarius, a collection of internationally recognized standards, codes of practice, guidelines and other recommendations relating to foods, food production and food safety. These texts are drawn up by the Codex Alimentarius Commission, an organization that is sponsored by the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO).
The Food Supplements Directive of 2002 requires that supplements be demonstrated to be safe, both in quantity and quality. Some vitamins are essential in small quantities but dangerous in large quantities, notably Vitamin A. Consequently, only those supplements that have been proven to be safe may be sold without prescription. As a category of food, food supplements cannot be labeled with drug claims in the bloc but can bear health claims and nutrition claims.
A survey conducted in Ireland in 2001, of adults aged 18-64 years, suggested that with the possible exception of niacin (flushing) and vitamin B6 (neuropathy), there appears to be little risk of the occurrence of adverse effects due to excessive consumption of vitamins in this population, based on current dietary practices.
The dietary supplements industry in the UK, one of the 27 countries in the European Union, strongly opposed the Directive. In addition, a large number of consumers throughout Europe, including over one million in the UK, and many doctors and scientists, had signed petitions by 2005 against what are viewed by the petitioners as unjustified restrictions of consumer choice. In 2004, along with two British trade associations, the Alliance for Natural Health had a legal challenge to the European Union's Food Supplements Directive referred to the European Court of Justice by the High Court in London. Although the European Court of Justice's Advocate General subsequently said that the EU's plan to tighten rules on the sale of vitamins and food supplements should be scrapped, he was eventually overruled by the European Court, which decided that the measures in question were necessary and appropriate for the purpose of protecting public health. ANH, however, interpreted the ban as applying only to synthetically produced supplements—and not to vitamins and minerals normally found in or consumed as part of the diet. Nevertheless, the European judges did acknowledge the Advocate General's concerns, stating that there must be clear procedures to allow substances to be added to the permitted list based on scientific evidence. They also said that any refusal to add a product to the list must be open to challenge in the courts.
Russian legislation, Ministry of Health's order number 117 dated as of 15 April 1997, under the title "Concerning the procedure for the examination and health certification of Biologically Active Dietary Supplements", provides the usage of the following terminology:
The development of BADSs and their applications has been very fast moving. They were originally considered as dietary supplements for people who had heightened requirements for some normal dietary components (for example, sportsmen). Later, they were employed as preventive medicines against chronic diseases.
In the United States, a dietary supplement is defined under the Dietary Supplement Health and Education Act of 1994 (DSHEA) as a product that is intended to supplement the diet and contains any of the following dietary ingredients:
Furthermore, it must also conform to the following criteria:
Pursuant to the DSHEA, the Food and Drug Administration (FDA) regulates dietary supplements as foods, and not as drugs. While pharmaceutical companies are required to obtain FDA approval proving the safety or effectiveness of their products prior to their entry into the market, dietary supplements, like food, do not need to be pre-approved by FDA before they can enter the market.
The DSHEA gave the FDA the express responsibility to regulate the manufacturing processes of dietary supplements, and the FDA issued its first proposed rule in 2003. In June 2007 it issued its final rule, which requires all dietary supplement manufacturers to ensure by June 2010 that production of dietary supplements complies with current good manufacturing practices, and be manufactured with "controls that result in a consistent product free of contamination, with accurate labeling." In addition, the industry is now required to report to the FDA "all serious dietary supplement related adverse events." The new rules have been criticized, however, with skeptics arguing lack of FDA resources, loopholes, and an exception on quality assurance for raw material suppliers (with the burden placed on manufacturers) will lead to continued quality problems. There's also concern that supplement manufacturers and retailers will hide behind the new regulations. Prior to the rule supplements have had major quality problems, and the number of FDA investigators has declined.
The DSHEA, passed in 1994, was the subject of lobbying efforts by the manufacturers of dietary supplements. At the time of its passage DSHEA received strong support from consumer grassroots organizations and members of Congress. In recognition of this, President Bill Clinton, on signing DSHEA into law, stated that "After several years of intense efforts, manufacturers, experts in nutrition, and legislators, acting in a conscientious alliance with consumers at the grassroots level, have moved successfully to bring common sense to the treatment of dietary supplements under regulation and law." He also noted that the passage of DSHEA "speaks to the diligence with which an unofficial army of nutritionally conscious people worked democratically to change the laws in an area deeply important to them" and that "In an era of greater consciousness among people about the impact of what they eat on how they live, indeed, how long they live, it is appropriate that we have finally reformed the way government treats consumers and these supplements in a way that encourages good health."
Popular support may have been based on a misunderstanding of the situation after the deregulation of the supplement industry. A large survey by the AARP, for example, found that 77% of respondents (including both users and non-users of supplements) believed that the federal government should review the safety of dietary supplements and approve them before they can be marketed to consumers. In an October 2002 nationwide Harris poll, 59% of respondents believed that supplements had to be approved by a government agency before they could be marketed; 68% believed that supplements had to list potential side effects on their labels; and 55% believed that supplement labels could not make claims of safety without scientific evidence. All of these beliefs were incorrect as a result of provisions of the DSHEA.
A 2001 study, published in Archives of Internal Medicine, found broad public support for greater governmental regulation of dietary supplements than was currently permitted by DSHEA. The researchers found that a majority of Americans supported pre-marketing approval by the FDA, increased oversight of harmful supplements, and greater scrutiny of the truthfulness of supplement label claims.
Under the FDA's final rule on good manufacturing practices, quality is defined as meaning "that the dietary supplement consistently meets the established specifications for identity, purity, strength, and composition and has been manufactured, packaged, labeled, and held under conditions to prevent adulteration under section 402(a)(1), (a)(2), (a)(3), and (a)(4) of the Federal Food, Drug, and Cosmetic Act". The new regulations allow FDA inspectors to look at a company's records upon request. However, enforcement could be difficult given the number of supplement manufacturers and the 16% decline in FDA investigators from 2003 to 2006. Much of the contamination is due to poor raw ingredients. Suppliers provide certificates of analysis stating that they have tested the material. Under the 2003 proposed rule, manufacturers would have been required to retest the supplied ingredients. Under the final rule, testing for identity is always required. Other retesting is not required if the manufacturer has verified the reliability of the ingredient supplier.
In the U.S., contamination and false labeling are "not uncommon". Independent certification programs exist, but these may have problems as well. United States Pharmacopeia manages the Dietary Supplement Verification Program (DSVP). Its USP Verified Mark seal indicates that the product has been tested for integrity, purity, dissolution, and safe manufacturing, and it is the only certification program which conducts random off-the-shelf testing. The USP program will not certify products which contain ingredients that the USP's Dietary Supplement Information Expert Committee determines have a safety risk. ConsumerLab.com randomly tests some dietary supplements and makes the results available to subscribers. It has reported that 25% of the supplements it tests have problems, and for multivitamins about half had problems. In 2008 ConsumerLab criticized the USP for proposing a 10 microgram perdaily serving limit on lead in dietary supplements and drugs. It noted that under the FDA's 2006 guidance on lead in candy, only 0.2 micrograms of lead per serving are allowed. NSF International, HFL Sport Science, and the Natural Products Association also have a dietary supplement certification programs.
If a dietary supplement claims to cure, mitigate, or treat a disease, it would be considered to be an unauthorized new drug and in violation of the applicable regulations and statutes. As the FDA states it in a response to this question in a FAQ:
Is it legal to market a dietary supplement product as a treatment or cure for a specific disease or condition?
No, a product sold as a dietary supplement and promoted on its label or in labeling* as a treatment, prevention or cure for a specific disease or condition would be considered an unapproved--and thus illegal--drug. To maintain the product's status as a dietary supplement, the label and labeling must be consistent with the provisions in the Dietary Supplement Health and Education Act (DSHEA) of 1994.
*Labeling refers to the label as well as accompanying material that is used by a manufacturer to promote and market a specific product.
Dietary supplements are permitted to make structure/function claims. These are broad claims that the product can support the structure or function of the body (e.g., "glucosamine helps support healthy joints", "the hormone melatonin helps establish normal sleep patterns"). The FDA must be notified of these claims within 30 days of their first use, and there is a requirement that these claims be substantiated. In reality, misleading claims about supplements are common, particularly on poorly-regulated commercial websites. For example, the compound hydrazine sulfate is sold as a dietary supplement in the USA and promoted as a treatment for cancer, despite little evidence that it is either safe or effective.
Other claims that required approval from FDA include health claims and qualified health claims. Health claims are permitted to be made if they meet the requirements for the claims found in the applicable regulations. Qualified health claims can be made through a petition process, including scientific information, if FDA has not approved a prior petition.