The law defines dietary supplements in part as products taken by
mouth that contain a "dietary ingredient." Dietary ingredients include
vitamins, minerals, amino acids, and herbs or botanicals, as well as
other substances that can be used to supplement the diet.
Dietary
supplements come in many forms, including tablets, capsules, powders,
energy bars, and liquids. These products are available in stores
throughout the United States, as well as on the Internet. They are
labeled as dietary supplements and include among others
vitamin and mineral products
"botanical"
or herbal products—These come in many forms and may include plant
materials, algae, macroscopic fungi, or a combination of these
materials.
amino acid products—Amino acids are known as the building blocks of proteins and play a role in metabolism.
enzyme supplements—Enzymes are complex proteins that speed up biochemical reactions.
People
use dietary supplements for a wide assortment of reasons. Some seek to
compensate for diets, medical conditions, or eating habits that limit
the intake of essential vitamins and nutrients. Other people look to
them to boost energy or to get a good night's sleep. Postmenopausal
women consider using them to counter a sudden drop in estrogen levels.