Final answer:
Supplement companies are indeed required to notify the FDA if a supplement contains a new dietary ingredient, as mandated by the Dietary Supplement Health and Education Act of 1994.
Step-by-step explanation:
The correct answer to whether supplement companies are required to notify the U.S. Food and Drug Administration (FDA) if a supplement contains a new dietary ingredient is true. According to the requirements set forth by the Dietary Supplement Health and Education Act (DSHEA) of 1994, manufacturers have the responsibility of ensuring the safety of dietary supplements. However, they are also mandated to inform the FDA if they intend to market a supplement that contains a new dietary ingredient. This notification must be provided at least 75 days before the product is introduced to the market, along with the evidence that provides reasonable assurance that the ingredient is safe. Hence, the FDA does have some regulatory oversight in terms of supplements, primarily when it concerns new ingredients not previously included in the food supply.