Barbosa PR, Stabler SP, Trentin R, Carvalho FR, Luchessi AD, Hirata RD, Hirata MH, Allen RH, Guerra-Shinohara EM. Evaluation of nutritional and genetic determinants of total homocysteine, methylmalonic acid and S-adenosylmethionine/S-adenosylhomocysteine values in Brazilian childbearing-age women. Clin Chim Acta. 2008 Feb; 388(1-2):139-47.