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. Design: Lactating women (n = 42) were enrolled in a doubleblind, 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 mol/L. Dietary folate intake was not significantly different between groups (380 ± 19 g/d) and at 6 mo was correlated with plasma homocysteine in unsupplemented women (r = Ϫ0.53, P < 0.01) and with plasma folate in supplemented women (r = 0.49, P < 0.02). Conclusions: A dietary folate intake of Ϸ380 g/d may not be sufficient to prevent mobilization of maternal folate stores during lactation.Am J Clin Nutr 1999;69:285-92. KEY WORDSLactation, plasma folate, erythrocyte folate, milk folate, dietary folate intake, plasma homocysteine, women INTRODUCTIONThe B vitamin folate and its coenzymatic forms are essential for one-carbon transfer reactions, which are underlying events for protein, DNA, and RNA biosynthesis. Folate requirements are greatest during periods of growth, development, and reproduction but may not always be met because folate deficiency occurs frequently during these nutritionally vulnerable stages of life. It is estimated that, globally, up to one-third of pregnant and lactating women have some degree of folate undernutrition (1). In the United States alone, Ϸ15% of women show signs of suboptimal folate status as evidenced by low serum and erythrocyte folate concentrations (< 6.8 and < 340 nmol/L, respectively) (2).Substantial evidence now exists establishing a relation between enhanced folate intake during the periconceptual period and the prevention of neural tube defects (3, 4). Neural tube defects are among the most common birth defects in the United States and affect Ϸ1 in 1000 infants (5). Compromised maternal folate status during pregnancy is also linked to low birth weight (6) and abruptio placentae (7) and to disorders that affect maternal health. Low folate status is associated with cellular dysplasia, often the predecessor of cancerous lesions in the epithelial layer of the cervix and c...

Folate and vitamin B12 in relation to lactation: a 9-month postpartum follow-up study

“…As expected, we found a statistically significant inverse relation between tHcy and folate, also found in our preliminary cross-sectional investigation (Ramlau-Hansen et al, 2003) and in agreement with results from the double-blind, randomized, longitudinal supplementation trial by Mackey and Picciano (1999).…”

“…Several investigations show an increased risk of suboptimal folate status (Matoth et al, 1965;Donangelo et al, 1989;Lehti, 1989;Ramlau-Hansen et al, 2003;Villalpando et al, 2003) and a reduction in folate stores during the lactation period (Shapiro et al, 1965;Tamura et al, 1980;Butte et al, 1981;Sneed et al, 1981;Smith et al, 1983;Dostalova, 1984;Bruinse et al, 1985;Bates et al, 1986;Salmenpera et al, 1986;Keizer et al, 1995;Mackey and Picciano, 1999) in women with no folic acid supplementation and with a diet insufficient in folate. Others have shown that lactation does not affect the level of folate (Cole et al, 1974;Thomas et al, 1980;Ek, 1983).…”

“…To our knowledge, very few investigations on the relationship between lactation and tHcy have been conducted (Mackey and Picciano, 1999;Ramlau-Hansen et al, 2003) and no study on the relationship between lactation and MMA exists.…”

Integration of physiological and molecular mechanisms of the developmental origins of adult disease: new concepts and insights

“…It is conceivable that lactational performance could be affected because folic acid supplementation can impair folate secretion into milk (Mackey & Picciano, 1999). It also disrupts the normal inverse relationship between dietary folate and plasma homocysteine (Mackey & Picciano, 1999), which may be related to changes in maternal folic acid metabolism (Smith et al 1983).…”

A longitudinal study of serum cobalamins and its binding proteins in lactating women

“…The requirements for many micronutrients such as vitamin B 12 are higher during pregnancy and lactation owing to transfer to the baby (Allen, 1994;Mackey and Picciano, 1999). A few studies have shown that the vitamin B 12 status of the mother is associated with the content of vitamin B 12 in breast milk (Baker et al, 1962;Black et al, 1994) and with the vitamin B 12 status of the baby (Specker et al, 1988), indicating that the amount of vitamin B 12 released into the breast milk and thereby available to the baby depends on the vitamin B 12 status of the mother.…”