Human milk folate and folate status in lactating mothers and their infants.

Plasma and red blood cell folate levels of healthy, well-nourished lactating mothers were measured. Folate levels in their breast-fed infants were significantly higher than in the mothers. No abnormal hematological findings were observed in either mothers or infants. Folate levels in breast milk and in the infants' plasma were significantly correlated. The mean breast-milk folate level was 141.4 ng/ml. The total daily folate intake for breast-fed infants was assessed at 14 to 25 micrograms/kg body weight. The plasma and red blood cell folate levels of the lactating mothers were significantly increased after oral administration of 1 mg pteroylmonoglutamate daily for 4 weeks. However, milk folate level did not change.