Thurmon T F
Louisiana State University School of Medicine, Shreveport, Louisiana, USA.
J La State Med Soc. 2001 Feb;153(2):98-103.
Folic acid is an essential micronutrient that merits special attention. In spite of plentiful sources in a balanced diet, recent data indicate that folic acid intake of many persons has long been inadequate. To some degree, this is due to destruction of folic acid by storage and processing of foodstuffs and to dietary practices that vary from recommendations. However, the common hereditary thermolabile variant of methylenetetrahydrofolate reductase (MTHFR) imposes an increased folic acid requirement which, if not met, may result in recurrent early pregnancy loss, anomalous progeny, thrombotic disorders, and cancers. There are recent reports that folic acid metabolism is also altered by other hereditary variations of MTHFR and other enzymes involved in folic acid metabolism. Optimal management requires dietary guidance and, for many patients, folate supplements. Caution is required because mandated folate fortification of grain products may produce levels that are inadequate for some patients and excessive for others. Laboratory tests for red cell folate and serum homocysteine are valuable adjuncts.
叶酸是一种值得特别关注的必需微量营养素。尽管均衡饮食中有丰富的来源，但最近的数据表明，许多人的叶酸摄入量长期不足。在某种程度上，这是由于食品储存和加工过程中叶酸的破坏以及与建议不同的饮食习惯。然而，亚甲基四氢叶酸还原酶（MTHFR）常见的遗传性热不稳定变体增加了对叶酸的需求，如果得不到满足，可能会导致反复早期流产、子代异常、血栓性疾病和癌症。最近有报道称，MTHFR的其他遗传变异以及参与叶酸代谢的其他酶也会改变叶酸代谢。最佳管理需要饮食指导，对许多患者来说，还需要补充叶酸。需要谨慎，因为强制在谷物产品中强化叶酸可能会使某些患者的叶酸水平不足，而对另一些患者则过量。红细胞叶酸和血清同型半胱氨酸的实验室检测是有价值的辅助手段。
