Final answer:
The Dietary Supplement Health and Education Act (DSHEA) of 1994 is the act that defines dietary supplements as food and lays out the regulations for their safety, manufacturing, and labeling.
Step-by-step explanation:
The act that states dietary supplements are considered food is the Dietary Supplement Health and Education Act (DSHEA) of 1994. The DSHEA stipulates that dietary supplements do not need approval from the U.S. Food and Drug Administration (FDA) before being marketed, unlike pharmaceutical drugs. It places the responsibility for the safety of these supplements in the hands of the manufacturers. Furthermore, under this act, dietary supplements are subject to the FDA's Good Manufacturing Standards, but they can only make limited claims about their effects on health and must include a disclaimer that they are not intended to "diagnose, treat, cure, or prevent any disease."