As part of a @-@ wk feeding trial , pregnant ( @-@ wk gestation ; n = @ ) , lactating ( @ wk postpartum ; n = @ ) , and control ( nonpregnant , nonlactating ; n = @ ) women consumed vitamin B-@ amounts of @ g/d -LSB- mixed diet ( @ g/d ) plus a prenatal multivitamin supplement ( @ g/d ) -RSB- .