From April 1990 to March 2000, the overall rate of preeclampsia did not significantly change before (3.8%) and after (3.7%) the introduction of a mandatory Canadian folic acid food fortification program in January 1998.
Both folate deficiency and elevated plasma homocysteine are associated with an increased risk of the placenta-mediated diseases of pregnancy, including preeclampsia-eclampsia (PET).1 By January 1998, flour producers were fortifying all Canadian flour in compliance with a mandatory national program, providing an additional daily average of 0.1 mg of folic acid (G. Carson, Robin Hood Multifoods Inc, Markham, Ontario, written communication, August 2000). We conducted a retrospective population-based longitudinal study to assess whether the introduction of this folic acid fortification program was associated with a decline in the rate of PET and all hypertensive disorders of pregnancy.
Ray JG, Mamdani MM. Association Between Folic Acid Food Fortification and Hypertension or Preeclampsia in Pregnancy. Arch Intern Med. 2002;162(15):1776–1777. doi: