Modeling shows high potential of folic acid-fortified salt to accelerate global prevention of major neural tube defects

Birth Defects Res. 2020 Nov;112(18):1461-1474. doi: 10.1002/bdr2.1769. Epub 2020 Aug 1.

Abstract

Background: We estimated the global proportion of folic acid-preventable spina bifida and anencephaly (FAP SBA) potentially prevented through mandatory double fortification of iodized salt with folic acid.

Methods: Using United Nations Children's Fund (UNICEF) and Global Fortification Data Exchange (GFDx) data sets, we modeled country-specific number of FAP SBA cases prevented annually using (a) current coverage of the salt in households worldwide and (b) expected daily amount of folic acid intake from folic acid-fortified iodized salt. Our evidence-based modeling strategy assumed mandatory folic acid fortification of salt at 20 ppm, and that at 200 μg/day intake of folic acid through fortified salt, should achieve 100% prevention of all FAP SBA in countries.

Results: One hundred countries that have data on percent of households consuming iodized salt globally were examined; 55 of them have ≥80% households consuming iodized salt. Our model estimated approximately 180,000 cases of FAP SBA could be prevented in these 100 countries through folic acid-fortified iodized salt, and 150,000 of them would be in countries where ≥80% households consuming iodized salt that can be potentially fortified with folic acid. Salt fortification with folic acid could contribute to the prevention of about 65% global FAP SBA cases annually.

Conclusions: Our evidence-based model shows that there is high potential to prevent FAP SBA using folic acid-fortified iodized salt. Prevention will reach countries where there is a limited reach of centrally processed folic acid-fortified wheat or maize flour. If this intervention is made feasible by the salt industry, it can accelerate the prevention of FAP SBA significantly.

Keywords: anencephaly; folic acid; fortification; neural tube defects; prevention; salt; spina bifida.