Folic acid and neural tube defects (1991-1998)
The 1991 MRC Vitamin Study randomized 1,817 women who had previous neural tube defect pregnancies and showed folic acid cut recurrence by 72%. The U.S. began mandating folic acid fortification of enriched grains in 1998, and spina bifida rates fell sharply.
Fortification became national policy within seven years of the trial.
A routinely fortified nutrient now prevents thousands of birth defects a year in the U.S.
It is the model for moving a prenatal nutrient from randomized trial to population-wide recommendation, the path choline's supporters envision.
