Iowa State University Extension

Before the United States congress passed the Dietary Supplement Health and Education Act (DSHEA) in 1994, the term "dietary supplement" referred to products made of one or more of the essential nutrients, such as vitamins, minerals, and protein. DSHEA expanded the definition stating that herbs, or other botanicals (except tobacco), and any dietary substance that can be used to supplement the diet were to be included in the definition.

This has lead to many new dietary supplements, for example:

• amino acids

• extracts from animal glands

• fibers such as psyllium and guar gum

• compounds not generally recognized as foods or nutrients such as enzymes and hormone-like compounds

This new definition has meant that many substances that the FDA formerly classified as drugs or unapproved food additives have become readily available as dietary supplements. For example, the synthetically manufactured prohormones melatonin and dehydroepiandrosterone (DHEA) that exert drug-like effects on the body are now classified as dietary supplements.

For more information, explore:

• Classifications of dietary supplements

• Index to individual dietary supplements

• Can supplements benefit you?