Vitamin B6 nutriture during pregnancy.

The vitamin B6 nutriture was determined during pregnancy beginning at month II until term by means of determination of pyridoxal phosphate in serum of 16 healthy pregnant women. During pregnancy, a biochemical vitamin B6 deficiency occurs gradually. The most significant decrease of pyridoxal phosphate parallels the time of most intensive growth and energy retention of the fetus. Vitamin B6 nutriture of mothers at the onset of pregnancy as well as the decrease of pyridoxal phosphate during pregnancy are in a positive correlation with birth weight of newborns. The most important mechanism leading to maternal vitamin B6 deficiency seems to be the active diaplacental transport of pyridoxal phosphate from mother to fetus. A vitamin B6 supplementation during pregnancy is necessary.