Adequacy of maternal pyridoxine supplementation during pregnancy in relation to the vitamin B₆ status and growth of neonates at birth

To evaluate the adequacy of maternal pyridoxine supplementation during pregnancy for both maternal and neonatal status-at birth, vitamin B₆ status, assessed by plasma pyridoxal phosphate (PLP), pyridoxal (PL) and total aldehyde vitamer (PLP+PL) concentrations, and the growth of neonates, including weight, length, head and chest circumferences, were examined for 209 neonates whose mothers were supplemented with 0, 1, 2 or 3 mg pyridoxine·HCl (PN·HCl)/d during pregnancy. Maternal PN·HCl supplementations were positively correlated to both maternal (r=0.62) and cord (r=0.78) plasma PLP concentrations (p <0.0001). Mothers supplemented with 2 or 3 mg/d PN·HCl had significantly higher plasma concentrations of PLP and total B₆ aldehyde vitamer in maternal and cord blood compared with those receiving 0 or 1 mg PN·HCl/d. A growth benefit for neonates whose mothers had maternal and cord plasma PLP concentrations ≥40 nM was revealed by the maternal supplementation of 2 mg PN·HCl/d during pregnancy. Thus, in healthy pregnant women, according to our study, a daily supplement of 2 mg PN·HCl provides the adequacy of maternal and neonatal vitamin B₆ status and the satisfactory growth of neonates at birth.