[Socio-demographic, lifestyle, gynecological, and obstetric predictors of serum or plasma concentrations of homocysteine, folic acid, and vitamins B12 and B6 among low-income women in São Paulo, Brazil].

[Socio-demographic, lifestyle, gynecological, and obstetric predictors of serum or plasma concentrations of homocysteine, folic acid, and vitamins B12 and B6 among low-income women in São Paulo, Brazil].