In an article in New Engl J of Med 2007, 357, 135-42 it was an article
Neural tube defects and fortification of flour with folic acid.
In 1998 the Canadian Government decreed that cereal products should be fortified with folic acid.
Following which there has been a 46% reduction in all neural tube defects , spina bifida reduced by 46%, and anencephaly by 38%.
Canadian Millers add 0.15 mg of folic acid to each 100 g flour and 0.25mg to pasta.
This gives an extra 150ųg per day.
The USA also fortified cereal and pasta flour in 1998 but the overall decrease is 28%
- Martin Eastwood