Am J Clin Nutr杂志发表一项叶酸补充研究，红细胞与血浆叶酸浓度之间的关系受到BMI和基因型的影响，而血浆维生素B12含量低则在很大程度上影响红细胞与血浆叶酸浓度的关系。
该研究分析一项基于人群的随机叶酸补充试验的育龄妇女(n = 1673)的数据，通过补充叶酸开始的时间、叶酸剂量、亚甲基四氢叶酸还原酶(MTHFR)基因型、体重指数(BMI)、维生素B12状态或贫血状态来估计与红细胞叶酸不足阈值（RBCf-IT）相对应的血浆叶酸不足阈值（pf – IT）。
主要结论：
1.与906 nmol/L的RBCf-IT相对应的基于人群的中位数pf-IT为25.5 nmol/L(95%可信区间:24.6,26.4)。
2. 补充叶酸后，估计中位pf-IT没有实质性的变化(25.7 nmol/L与25.2 nmol/L相比)，MTHFR基因型和BMI只有适度的变化（中度差异±3-4 nmol/L）。
3.维生素B12缺乏的女性的估计中位数pf-IT远高于维生素B12充足的女性，25.5 nmol/L的最佳NTD预防阈值可能适用于具有相似特征的人群，但不适用于维生素B12不足的人群。
来源：Defining the plasma folate concentration associated with the red blood cell folate concentration threshold for optimal neural tube defects prevention: a population-based, randomized trial of folic acid supplementation .Am J Clin Nutr.2019 May 1;109(5):1452-1461.
泰乐德医疗NTD预防解决方案
●红细胞叶酸检测
近年来，经研究证明红细胞中叶酸含量是血清中叶酸的含量的10~20倍，受外界因素的干扰很少，更能真实地反映组织中叶酸的浓度水平和长期储存水平，仅仅测定血清叶酸含量不能满足临床医学的要求。
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