Changes in Plasma Pyridoxal 5'-Phosphate Concentration during Pregnancy Stages in Japanese Women

Abstract

Most Japanese women do not consume the estimated average requirement of vitamin B6 (1.7 mg/d) during pregnancy. Nevertheless, these deficiencies are not reported. We investigated a nutritional biomarker of vitamin B6 in pregnant Japanese women as well as their vitamin B6 intakes. Vitamin B6 intakes in the first, second, and third trimesters of pregnancy, and 1 mo after delivery were 0.79±0.61 (n=56), 0.81±0.29 (n=71), 0.90±0.35 (n=92), and 1.00±0.31 (n=44) mg/d, respectively. Plasma pyridoxal 5'-phosphate (PLP) concentrations in the first, second, and third trimesters of pregnancy, and 1 mo after delivery were 57.1±27.6 (n=56), 23.3±16.7 (n=71), 18.3±12.5 (n=92), and 43.9±33.4 (n=44) nmol/L, respectively. The plasma concentrations significantly decreased in the second and third trimesters of pregnancy compared to values from the first trimester (p<0.05), and these concentrations returned to the values of the first trimester of pregnancy 1 mo after birth.

Suboptimal maternal and cord plasma pyridoxal 5′ phosphate concentrations are uncommon in a cohort of Canadian pregnant women and newborn infants

“…Maternal plasma PLP concentrations decreased from early to late pregnancy in our study, which is consistent with previous observations (Fayyaz et al, ; Shibata et al, ; Takimoto et al, ). Interestingly, there were distinct opposing trends across pregnancy depending on the mother's plasma PLP status in early pregnancy: Plasma PLP concentrations increased during pregnancy in those with plasma PLP concentrations <20 nmol/L in early pregnancy, and the opposite trend was observed in those with plasma PLP concentrations ≥20 nmol/L in early pregnancy.…”

“…In our cohort, 6.8% and 14.3% of women had plasma PLP <30 nmol/L in early pregnancy and at delivery, respectively. A study from Japan found 16%, 82%, and 84% of pregnant women had plasma PLP concentrations <30 nmol/L in the 1st, 2nd, and 3rd trimesters, respectively (Shibata et al, ). This is not surprising considering these women were not taking supplements, and their dietary vitamin B 6 intakes were considerably low (<1.0 mg per day; Shibata et al, ).…”

“…A study from Japan found 16%, 82%, and 84% of pregnant women had plasma PLP concentrations <30 nmol/L in the 1st, 2nd, and 3rd trimesters, respectively (Shibata et al, ). This is not surprising considering these women were not taking supplements, and their dietary vitamin B 6 intakes were considerably low (<1.0 mg per day; Shibata et al, ). Another Japanese study reported 100% of pregnant women had plasma PLP concentrations <30 nmol/L, again likely relating to lower vitamin B 6 intake compared with North America (Takimoto et al, ).…”

“…In cord plasma, PLP concentrations were weakly inversely, albeit nonsignificantly, correlated with homocysteine concentrations (r = −.13, p = .06). (Shibata et al, 2013). This is not surprising considering these women were not taking supplements, and their dietary vitamin B 6 intakes were considerably low (<1.0 mg per day; Shibata et al, 2013).…”

Impact of Pre-Pregnancy BMI on B Vitamin and Inflammatory Status in Early Pregnancy: An Observational Cohort Study

“…Folate, cobalamin, and PLP tend to decrease, whereas riboflavin is reported to show only minor changes during pregnancy [38,39,40,41,42]. tHcy, a marker of folate and cobalamin deficiency [43], is 30%–60% lower in pregnant compared to nonpregnant women, with the lowest levels seen in the second trimester [44].…”