After randomized, controlled trials established that consumption of folic acid before pregnancy and during the early weeks of gestation reduces the risk of a neural tube defect (NTD)-affected pregnancy, the United States Public Health Service recommended in 1992 that all women capable of becoming pregnant consume 400 microg folic acid daily. In 1998, folic acid fortification of all enriched cereal grain product flour was fully implemented in the United States and Canada.
To provide guidance on national fortification of wheat and maize flours to prevent 50 to 70% of the estimated 300,000 NTD-affected pregnancies worldwide.
An expert workgroup reviewed the latest evidence of effectiveness of folic acid flour fortification and the safety of folic acid.
Recent estimates show that in the United States and Canada, the additional intake of about 100 to 150 microg/day of folic acid through food fortification has been effective in reducing the prevalence of NTDs at birth and increasing blood folate concentrations in both countries. Most potential adverse effects associated with folic acid are associated with extra supplement use not mandatory fortification. Fortification of wheat flour has a proven record of prevention in other developed countries. In 2009, 51 countries had regulations written for mandatory wheat flour fortification programs that included folic acid.
NTDs remain an important cause of perinatal mortality and infantile paralysis worldwide. Mandatory fortification of flour with folic acid has proved to be one of the most successful public health interventions in reducing the prevalence of NTD-affected pregnancies. Most developing countries have few, if any, common sources of folic acid, unlike many developed countries, which have folic acid available from ready-to-eat cereals and supplements. Expanding the number of developed and developing countries with folic acid flour fortification has tremendous potential to safely eliminate most folic acid-preventable NTDs.