Number range CHAPTER**Background Summary and Charge to the
Subcommittee**

In 1994, Congress passed the Dietary Supplement Health and Education Act
(DSHEA) (P.L. 103-417). This law amended the Federal Food, Drug, and
Cosmetic Act (the Act) (21 U.S.C. 301 *et seq.*). Among other things,
DSHEA defined the term "dietary supplement." (*See* 21 U.S.C. §
321(ff)). Part of this statutory definition states that a "dietary
supplement" is a product (other than tobacco) intended to supplement the
diet that bears or contains one or more of the following dietary
ingredients:

-   a vitamin

-   a mineral

-   an herb or other botanical

-   an amino acid

-   a dietary substance for use by man to supplement the diet by
    increasing the total dietary intake; or

-   a concentrate, [metabolite]{.underline}, constituent, extract, or
    combination of any ingredient named above.

The plain language of the Act and the statement of agreement that
constitutes the legislative history of DSHEA do not provide an
explanation of the scope or nature of the substances intended to be
encompassed by the term "metabolite." The ordinary, usual meaning of the
term is of limited usefulness in identifying substances that may be
encompassed by the term "metabolite." For example, the term "metabolite"
is defined differently by dictionaries and other reference sources:

-   A product of metabolism; a substance essential to the metabolism of
    a particular organism or a particular metabolic process
    \[Merriam-Webster Dictionary\]

-   Any substance produced by metabolism or by a metabolic process \[The
    Cancer WEB Project, [cancerweb.ncl.ac.uk]{.underline}\]

-   Any product or substrate (foodstuff, intermediate, waste product) of
    metabolism especially catabolism \[Stedman's Medical Dictionary,
    [www.stedmans.com]{.underline}\]

-   a product of metabolism; a metabolic waste usually more or less
    toxic to the organism producing it; a product of one process that is
    essential to another such process in the same organism; a metabolic
    waste of one organism that is markedly toxic to another; a substance
    essential to the metabolism of a particular organism or to a
    particular metabolic process \[FastHealth Interactive Healthcare,
    [www.fasthealth.com]{.underline}\]

These definitions appear to suggest that any substance present in an
organism is a "metabolite." The definitions, however, do not address
[when]{.underline} a particular substance is a metabolite of another
dietary ingredient.[^1] This fact is important to determining whether a
substance is a dietary ingredient for purposes of identifying a "dietary
supplement" under the Act. Therefore, in the context of substances that
are produced and utilized in metabolic systems, the basic question at
hand with respect to defining the term "metabolite" is whether it is
possible to identify particular scientific criteria, principles, or
conventions that enable a determination to be made about when a
substance is or is not a metabolite of another dietary ingredient.

[^1]: For present purposes, "another dietary ingredient" means a
    vitamin, mineral, herb or other botanical, amino acid, or dietary
    substance for use by man to supplement the diet by increasing the
    total dietary intake.