Supporting Healthy Mothers and Infants Act of 2023 This bill modifies the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) to add requirements for supporting individuals impacted by a substance use disorder. Specifically, the bill requires the Department of Agriculture to collaborate with the Department of Health and Human Services (HHS) to develop and disseminate nutrition education materials for individuals impacted by a substance use disorder, including materials for infants impacted by prenatal substance exposure and neonatal abstinence syndrome; conduct outreach to individuals who are potentially eligible for the WIC program and who are impacted by such a disorder; and make available to states through an online clearinghouse any nutrition education and training materials related to nutrition for individuals impacted by a substance use disorder or neonatal abstinence syndrome. In addition, the nutrition education materials developed in collaboration with HHS must be included in (1) Center for Substance Abuse Prevention-developed education materials, and (2) HHS guidance on improving care for infants with neonatal abstinence syndrome and their families.