Vitamin B6 nutriture during pregnancy and lactation. I. Vitamin B6 intake, levels of the vitamin in biological fluids, and condition of the infant at birth

Because pregnant and lactating women need more vitamin B6 for fetal and infant DNA synthesis and development of the central nervous system, maternal vitamin B6 nutriture needs to be assessed. Blood and urine samples were taken from 86 women at 5 and 7 months gestation, 102 at delivery, and 61 during lactation. Mean vitamin B6 intake was 1.24 mg/day before supplementation and 6.2 mg/day after. The mean vitamin B6 level in the serum at delivery and in cord serum was significantly lower with intake below daily allowance. Although levels in milk were significantly higher at 3 days postpartum for intakes above the daily allowance, it was not different at 14 days, but the vitamin B6:protein ratio was higher. Mothers of infants with Apgar scores below 7 at 1 min had lower vitamin B6 intake and levels in maternal serum at delivery and in milk, and the ratio in cord to maternal serum was significantly higher. Levels in maternal serum at 5 months gestation were significantly correlated with cord serum and milk levels at 14 days postpartum.