title: Maternal folate status during extended lactation and the effect of supplemental folic acid.
abstract: BACKGROUND
  Folate requirements during lactation are not well established.
  
  
  OBJECTIVE
  We assessed the effects of dietary and supplemental folate intakes during extended lactation.
  
  
  METHODS
  Lactating women (n = 42) were enrolled in a double-blind, randomized, longitudinal supplementation trial and received either 0 or 1 mg folic acid/d. At 3 and 6 mo postpartum, maternal folate status was assessed by measuring erythrocyte, plasma, milk, and dietary folate concentrations; plasma homocysteine; and hematologic indexes. Infant anthropometric measures of growth, milk intake, and folate intake were also assessed.
  
  
  RESULTS
  In supplemented women, values at 6 mo for erythrocyte and milk folate concentrations and for plasma homocysteine were not significantly different from those at 3 mo. In supplemented women compared with unsupplemented women at 6 mo, values for erythrocyte folate (840 compared with 667 nmol/L; P < 0.05), hemoglobin (140 compared with 134 g/L; P < 0.02), and hematocrit (0.41 compared with 0.39; P < 0.02) were higher and values for reticulocytes were lower. In unsupplemented women, milk folate declined from 224 to 187 nmol/L (99 to 82 ng/mL), whereas plasma homocysteine increased from 6.7 to 7.4 micromol/L. Dietary folate intake was not significantly different between groups (380+/-19 microg/d) and at 6 mo was correlated with plasma homocysteine in unsupplemented women (r = -0.53, P < 0.01) and with plasma folate in supplemented women (r = 0.49, P < 0.02).
  
  
  CONCLUSIONS
  A dietary folate intake of approximately 380 microg/d may not be sufficient to prevent mobilization of maternal folate stores during lactation.
authors.affiliation: Department of Nutrition, The Pennsylvania State University, University Park 16802, USA.
authors.forename: A D
authors.initials: AD
authors.lastname: Mackey
authors.forename: M F
authors.initials: MF
authors.lastname: Picciano
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000886:Anthropometry; D002657:Child Development; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage* / Q000032:analysis* / Q000097:blood; D006403:Hematologic Tests; D006710:Homocysteine / Q000097:blood; D006801:Humans; D007231:Infant, Newborn; D007774:Lactation / Q000378:metabolism*; D008137:Longitudinal Studies; D008895:Milk, Human / Q000737:chemistry