Wald Nicholas J, Morris Joan K, Blakemore Colin
1Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ UK.
2Centre for the Study of the Senses, School of Advanced Study, University of London, London, UK.
Public Health Rev. 2018 Jan 31;39:2. doi: 10.1186/s40985-018-0079-6. eCollection 2018.
The neural tube defects anencephaly and spina bifida are two of the most common serious congenital malformations. Most cases can be prevented by consuming sufficient folic acid immediately before pregnancy and in early pregnancy. Fortification of flour with folic acid to prevent these defects has been implemented in 81 countries without public objection or indication of harm. An obstacle to the wider adoption of fortification arises from the creation of a "tolerable upper intake level" for folate (which includes natural food folate as well as synthetic folic acid), and which has been set at 1 mg/day, thereby proscribing higher folate intakes. Increasing the intake of folic acid in a population will necessarily increase the number of people with a folate intake greater than 1 mg per day, and this concern is obstructing folic acid fortification. This paper shows that the scientific basis for setting any upper limit, let alone one at 1 mg/day, is flawed. An upper intake level is therefore unnecessary and should be removed, thus allaying unjustified concerns about folic acid fortification. As a result, the full global opportunity to prevent two serious fatal or disabling disorders can and should be realized.
神经管缺陷中的无脑儿和脊柱裂是两种最常见的严重先天性畸形。大多数病例可以通过在怀孕前和怀孕早期摄入足够的叶酸来预防。81个国家已实施面粉中添加叶酸以预防这些缺陷的措施，且未遭到公众反对或出现有害迹象。叶酸（包括天然食物叶酸以及合成叶酸）“可耐受最高摄入量”的设定成为更广泛采用强化措施的一个障碍，该摄入量被设定为每日1毫克，从而限制了更高的叶酸摄入量。增加人群中叶酸的摄入量必然会使每日叶酸摄入量超过1毫克的人数增加，而这种担忧阻碍了叶酸强化工作。本文表明，设定任何上限，更不用说每日1毫克这一上限的科学依据是有缺陷的。因此，最高摄入量是不必要的，应该取消，从而消除对叶酸强化的无端担忧。这样一来，预防两种严重的致命或致残疾病的全球充分机会就能够且应该得以实现。
