Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.
Keenan Research Center for Biomedical Science of St. Michael's Hospital, Toronto, Ontario, Canada.
Matern Child Nutr. 2018 Jan;14(1). doi: 10.1111/mcn.12467. Epub 2017 May 24.
Vitamin B is important in fetal development, but little is known of the vitamin B status of pregnant women and newborns in North America and potential modifying factors. This prospective study determined maternal and cord plasma concentrations of pyridoxal 5' phosphate (PLP; an indicator of vitamin B status) in a convenience sample of 368 Canadian pregnant women and their newborns. The association of maternal intake of vitamin B and fetal genetic variants with cord plasma PLP and homocysteine concentrations was also examined. Dietary and supplemental intakes of vitamin B were assessed in early and mid to late pregnancy. PLP concentrations were measured in maternal plasma in early pregnancy and at delivery, and in cord plasma. Six fetal variants of the MTHFR and CβS genes were assessed for their association with cord plasma PLP and homocysteine concentrations. Geometric mean (95% CI) PLP concentrations were 107 (98, 116) nmol/L in early pregnancy and 58 (53, 62) nmol/L at delivery, respectively, and 296 (275, 319) nmol/L in cord blood (p < .0001). During early pregnancy and at delivery, 3.6% and 5.5% of women had plasma PLP concentrations <20 nmol/L, respectively. Ninety eight percent of the women with supplemental B intake of at least the recommended dietary allowance had PLP concentrations >20 nmol/L. Fetal genetic variants were not associated with cord PLP and homocysteine concentrations. Vitamin B deficiency is uncommon in a cohort of Canadian pregnant women due largely to prevalent vitamin B supplement use.
维生素 B 对胎儿发育很重要，但北美的孕妇和新生儿的维生素 B 状况及其潜在的影响因素知之甚少。本前瞻性研究在加拿大的 368 名孕妇及其新生儿中，以便利样本的方式测定了母体和脐血浆中吡哆醛 5' 磷酸（PLP；维生素 B 状况的指标）的浓度。还研究了母体维生素 B 摄入量和胎儿遗传变异与脐血浆 PLP 和同型半胱氨酸浓度的关系。在妊娠早期和中晚期评估了维生素 B 的膳食和补充摄入量。在妊娠早期和分娩时测定了母体血浆中 PLP 浓度，并在脐血浆中测定了 PLP 浓度。评估了 MTHFR 和 CβS 基因的 6 个胎儿变异与脐血浆 PLP 和同型半胱氨酸浓度的关系。妊娠早期和分娩时的 PLP 浓度的几何均数（95%CI）分别为 107（98,116）nmol/L 和 58（53,62）nmol/L，脐血中为 296（275,319）nmol/L（p<.0001）。在妊娠早期和分娩时，分别有 3.6%和 5.5%的妇女的血浆 PLP 浓度<20 nmol/L。有 98%服用了至少推荐膳食允许量的补充维生素 B 的妇女其 PLP 浓度>20 nmol/L。胎儿遗传变异与脐血 PLP 和同型半胱氨酸浓度无关。由于普遍使用维生素 B 补充剂，加拿大孕妇队列中维生素 B 缺乏很少见。
