Cod liver oil contains long-chain omega-3 fatty acids, as well as vitamins D and A. It was a traditional source of vitamin D in the United States and was used to prevent and treat rickets. In our clinical research, we used liquid cod liver oil of adequate purity and acceptable taste for infants and young children, as well as a children's multivitamin/mineral supplement with selenium and other trace metals. In a cluster-randomized study of pediatric visits for upper respiratory illness during the winter and early spring, these nutritional supplements decreased mean visits/subject/month by 36%-58%. Cod liver oil is culturally valued and has been used as a folk remedy by many low-income minorities in the United States. Nutritional supplements cannot be purchased with SNAP benefits (formerly called food stamps). Inclusion of cod liver oil in state Medicaid formularies would make it available to low-income children, whose families may not be able to pay for it out-of-pocket.