Schroder Theresa H, Sinclair Graham, Mattman Andre, Jung Benjamin, Barr Susan I, Vallance Hilary D, Lamers Yvonne
1Food, Nutrition and Health, Faculty of Land and Food Systems,The University of British Columbia,2205 East Mall,Vancouver BC,V6T 1Z4,Canada.
2British Columbia Children's Hospital Research Institute,950 W 28Ave,Vancouver BC,V5Z 4H4,Canada.
Br J Nutr. 2017 Sep;118(6):454-462. doi: 10.1017/S0007114517002331. Epub 2017 Sep 18.
Maternal vitamin B12 (B12) status has been inversely associated with adverse pregnancy outcomes and positively with fetal growth and infant development. South Asians, Canada's largest ethnic minority, are prone to B12 deficiency. Yet, data are lacking on B12 status in South Asian pregnant women in North America. We sought to determine B12 status, using multiple biomarkers, in 1st and 2nd trimester pregnant women of South Asian and, for comparison, European ethnicity living in Vancouver, Canada. In this retrospective cohort study, total B12, holotranscobalamin (holoTC), methylmalonic acid (MMA), and total homocysteine concentrations were quantified in two routinely collected (mean gestational week: 11·5 (range 8·3-13·9) and 16·5 (range 14·9-20·9)), banked serum samples of 748 healthy pregnant South Asian (n 371) and European (n 377) women. South Asian pregnant women had significantly lower B12 status than European pregnant women at both time points, as indicated by lower serum total B12 and holoTC concentrations, and higher MMA concentrations (all P≤0·001). The largest difference, which was substantial (Cohen's d≥0·5), was observed in mean serum total B12 concentrations (1st trimester: 189 (95 % CI 180, 199) v. 246 (95 % CI 236, 257) pmol/l; 2nd trimester: 176 (95 % CI 168, 185) v. 226 (95 % CI 216, 236) pmol/l). Further, South Asian ethnicity was a significant negative predictor of B12 status during pregnancy. South Asian women living in Vancouver have substantially lower B12 status during early pregnancy. Future research identifying predictors and health consequences of this observed difference is needed to allow for targeted interventions.
母亲的维生素B12（B12）水平与不良妊娠结局呈负相关，与胎儿生长和婴儿发育呈正相关。南亚人是加拿大最大的少数族裔，容易出现B12缺乏。然而，北美南亚裔孕妇的B12水平数据尚缺。我们试图使用多种生物标志物来确定加拿大温哥华地区南亚裔和欧洲裔孕早期及孕中期孕妇的B12水平，并进行比较。在这项回顾性队列研究中，对748名健康的南亚裔（n = 371）和欧洲裔（n = 377）孕妇的两份常规采集（平均孕周：11.5（范围8.3 - 13.9）和16.5（范围14.9 - 20.9））的储存血清样本进行了总B12、全转钴胺素（holoTC）、甲基丙二酸（MMA）和总同型半胱氨酸浓度的定量分析。在两个时间点，南亚裔孕妇的B12水平均显著低于欧洲裔孕妇，表现为血清总B12和holoTC浓度较低，MMA浓度较高（所有P≤0.001）。在平均血清总B12浓度方面观察到最大差异，差异显著（科恩d值≥0.5）（孕早期：189（95%CI 180, 199）对246（95%CI 236, 257）pmol/L；孕中期：176（95%CI 168, 185）对226（95%CI 216, 236）pmol/L）。此外，南亚裔是孕期B12水平的显著负预测因子。居住在温哥华的南亚裔女性在孕早期的B12水平显著较低。需要进一步研究确定这一差异的预测因素和健康后果，以便进行有针对性的干预。
