Background: Doctors frequently advise individuals who may become pregnant to take prenatal supplements even prior to pregnancy, with the North American market for these supplements valued at about $200 million per year in 2020. Individuals who are or may become pregnant often use over-the-counter prenatal supplements for key vitamins and minerals--such as folic acid and iron--to prevent or reduce the risk of birth defects and for their own health. Federal labeling regulations require that all supplements have a supplement facts panel that includes a list of ingredients and associated quantity, and supplements that are inaccurately labeled are considered misbranded and are subject to Food and Drug Administration (FDA) enforcement action. Also, FDA has set limits on contaminants (arsenic, lead, etc.) in its food standards. However, FDA oversight of dietary supplements generally occurs after products are on the market. Key Questions: (1) To what extent do selected over-the-counter prenatal supplements contain the amounts of key vitamins and minerals stated on the label or contain potentially harmful unlabeled substances? (2) What is FDA's role in the oversight of prenatal supplements?