In the United States, a dietary supplement is defined under the Dietary Supplement Health and Education Act of 1994 as a product that meets each of the following criteria:
1. It is intended to supplement the diet and bears or contains one
or more of the following dietary ingredients:
The FDA regulates dietary supplements as foods, and not as drugs. The FDA does not pre-approve dietary supplements on their safety and efficacy, unlike drugs. In contrast, the FDA can only go after dietary supplement manufacturers after they have put unsafe products on the market. However, certain foods (such as infant formula and medical foods) are deemed special nutritionals because they are consumed by highly vulnerable populations and are thus regulated more strictly than the majority of dietary supplements.
The claims that a dietary supplement makes are essential to its classification. If a dietary supplement claims in any way to cure, mitigate, or treat a disease, it would be considered to be a unauthorized new drug and in violation of the applicable regulations and statutes. As the FDA states it:
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.
The only claims that a dietary supplement is allowed to make are 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"). These claims must be registered with the FDA ahead of time, and there is a requirement that these claims be substantiated. Nevertheless, many critics claim that dietary supplements overstate their importance and their impact on overall health.=
The Food Supplements Directive1 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. Some herbal remedies, notably St Johns Wort, are poisonous if taken with certain prescription drugs. Consequently, only those supplements that have been proven to be safe may be sold without prescription.
The dietary supplements industry in Europe strongly opposed the Directive, having been accustomed to a high-profit, laissez-faire, approach in some countries. Consumer Groups have welcomed2 the Directive, saying that it "will properly protect people who take supplements, ensuring that products are safe, that they contain forms of vitamins and minerals that offer some benefit, and that they are clearly labelled." (WHICH?, UK). The European Court of Justice ruled3 on 12 July 2005 that the Directive is valid. However, it made clear that it must be possible for manufacturers to add materials to the list, that refusal must be on scientific grounds, and that there should be a right to appeal.