This review is a non-systematic overview of articles published in English, German or French over the past decade. Thus, main emphasis is placed on results from western countries. Several earlier, commonly referenced, key publications are also cited. Unpublished findings presented in press releases were not considered. Articles were selected from the personal bibliographic databases of the authors and from a MEDLINE search with more than 40 key words including “folic acid”, neural tube
ReviewFolic acid: a public-health challenge
Section snippets
Effect of folic acid on risk of anomalies and disease
Two of the most common serious birth defects of the brain and spine are spina bifida and anencephaly. These neural tube defects occur when part of the neural tube, which later develops into spinal cord and brain, does not close. Closing normally happens around 24 days after conception—ie, before the woman has realised that she is pregnant. In the case of anencephaly all infants are stillborn or die shortly after birth, whereas in the case of spina bifida, children survive with lifelong
Recommendations
The evidence of the benefit of folic acid in prevention of neural tube defects has since 1992, led many health organisations to issue recommendations for women to maintain a healthy diet and take folic acid supplements (0·4 mg daily; to prevent neural tube defect recurrence: 4 mg daily) when planning a pregnancy or throughout childbearing age.28, 40 These recommendations might differ slightly: in Australia, for example, 0·5 mg folic acid daily is recommended.41 However, 0·4 mg per day was the
Safety of folic acid
Despite the noted beneficial effects of folic acid fortification on folate status and neural tube defects in countries that implemented either mandatory or voluntary fortification in addition to the promotion of supplement use, concern continues that folic acid might also have adverse effects.35 Although folate is safe and almost free of toxicity,108 concerns that folic acid fortification could mask symptoms of vitamin B12 deficiency and precipitate neurological complications have been raised.1
Public health implications
Despite public-health campaigns, knowledge about the proper periconceptional time to use folic acid supplements for the prevention of neural tube defects is not widespread in women and only a maximum of half of them are following the recommendations. Vulnerable groups are people of low educational status, young people, immigrants, and women with unplanned pregnancies. A substantial percentage of women still choose not to take the supplements even though they are aware of the beneficial effects.
Conclusions
In countries choosing mandatory fortification with folic acid, careful assessment of beneficial as well as potential negative health effects is of prime importance. In countries deciding against mandatory fortification, promotion and funding of research on additional effective means to improve folic acid supplement use is essential. At present, there exist only a few new strategies, which are not yet part of comprehensive folic acid campaigns worldwide. Thus, not only careful monitoring and
Search strategy and selection criteria
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