G1793A polymorphisms in the methylene-tetrahydrofolate gene: effect of folic acid on homocysteine levels - Melo, Sandra Soares; Persuhn, Darlene Camati; Meirelles, Mônica Silva de Souza; Jordão, Alceu Afonso; Vannucchi, Hélio (Molecular Nutrition & Food Research, 2006)