High folate and low vitamin B-12 intakes during pregnancy are associated with small-for-gestational age infants in South Indian women: a prospective observational cohort study

Background: Folic acid supplementation in those with a low vitamin B-12 intake or status may have adverse effects. These effects are unknown with regard to birth outcome in pregnant Indian women who are routinely supplemented with high doses of folic acid.Objective: The objective was to examine the association of unbalanced vitamin B-12 and total folate (folic acid supplement + dietary folate) intakes during pregnancy with outcomes in small-for-gestational-age (SGA) infants.Design: This was a prospective observational cohort study of 1838 pregnant women in South India. Low intake of dietary vitamin B-12 in the presence of high total folate intake was examined as the ratio of vitamin B-12 intake to total folate intake.Results: The inadequacy of vitamin B-12 intake (