Pyridoxal phosphate concentration in blood in newborn infants and their mothers compared with the amount of extra pyridoxol taken during pregnancy and breast feeding.

The concentrations of pyridoxal phosphate have been estimated in cord blood and capillary blood samples taken at 3 hours, 2 days, 4 days, 7 days and 6 weeks of age, from eleven full-term infants. Pyridoxal phosphate concentrations were also determined in venous blood samples taken from the mothers at delivery. A highly significant correlation between pyridoxal phosphate in cord whole blood and venous whole blood taken from the mothers at delivery was found. Infants whose mothers had taken extra pyridoxol during pregnancy had a higher concentration of pyridoxal phosphate at 3 hours of age compared with infants whose mothers had not taken extra pyridoxol. During the first week of life the concentrations of pyridoxal phosphate in capillary blood decreases strikingly. At 6 weeks of age the concentration of pyridoxal phosphate is in the same range as that of normal adults. Findings are also discussed which indicates that: 1) Vitamin B6 is transported in breast milk; 2) The giving of supplemental pyridoxol during pregnancy in ordinary doses (2-6 mg/day) does not have an antilactogenic effect. No correlation between the erythrocyte aspartate aminotransferase activation with pyridoxal phosphate in vitro and pyridoxal phosphate concentration in plasma was found during the first 6 weeks of life.