Folate and neural tube defects
Folate and neural tube defects
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DOI：
10.1093/ajcn/85.1.285s
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发表时间：
2007-01-01
影响因子：
7.1
通讯作者：
Pitkin, Roy M.
中科院分区：
文献类型：
--
作者：
Pitkin, Roy M.
叶酸对神经管缺陷（NTDs），特别是无脑畸形和脊柱裂的保护作用，在过去半个世纪的一系列临床研究中得到了广泛的认可。这篇文章总结了这些更重要的研究，这些研究导致了目前的情况，即所有有能力怀孕的女性都被敦促定期摄入叶酸。对于那些高危人群（由于之前的NTD妊娠结果），建议摄入量为4毫克/天，其他所有人建议摄入量为0.4毫克/天。然而，这些建议的颁布并没有减少新生儿的出生，所以叶酸强化在美国和其他一些国家是强制性的。尽管关于强化水平是否足够仍存在一些争议，但叶酸指数显著改善，NTD发病率降低了25-30%（约占假定对叶酸有反应的病例比例的一半）。叶酸- ntd关系代表了唯一的例子，其中先天性畸形可以简单和一致地预防。尽管如此，仍存在一些研究空白：确定缺陷发生的机制以及叶酸如何改善它；食品叶酸、添加到食品中的叶酸和叶酸本身相对功效的表征；叶酸与NTD预防的剂量-反应关系的描述；更精确地量化预防复发所需的剂量。
A protective effect of folate against the development of neural tube defects (NTDs), specifically, anencephaly and spina bifida, is now well recognized, having been established by a chain of clinical research studies over the past half century. This article summarizes the more important of these studies, which have led to the current situation in which all women capable of becoming pregnant are urged to ingest folic acid regularly. The recommended intakes are 4 mg/d for those at high risk (by virtue of a previous NTD pregnancy outcome) and 0.4 mg/d for all others. However, a reduction in NTD births did not follow promulgation of these recommendations, and so folic acid fortification was mandated in the United States and some other countries. Although some controversy remains about the adequacy of fortification levels, the process was followed by significant improvement in folate indexes and a reduction of 25-30% in NTD frequency (about one-half of the proportion of cases assumed to be responsive to folate). The folate-NTD relation represents the only instance in which a congenital malformation can be prevented simply and consistently. Nevertheless, several research gaps remain: identification of the mechanism by which the defect occurs and how folate ameliorates it; characterization of the relative efficacy of food folate, folic acid added to foods, and folic acid by itself; delineation of the dose-response relations of folate and NTD prevention; and more precise quantification of the dose needed to prevent recurrences.