Abundant scientific evidence has shown a link between maternal folic acid deficiency during early pregnancy and the development of neural tube defects in the fetus. The American Academy of Pediatrics recommends that “all women of childbearing age who are capable of becoming pregnant should consume 400 micrograms of folic acid daily.” For women who have had a child with a neural tube defect and women who themselves have a neural tube defect, the American Academy of Pediatrics recommends “4000 micrograms of folic acid per day starting 1 month before the time they plan to become pregnant and throughout the first 3 months of pregnancy, unless contraindicated.” For further details, please see Neural Tube Defects - AAP Policy Statement on Folic Acid Supplementation.

Although folic acid supplementation has decreased the incidence of neural tube defects in the United States from 25% to 45%, clearly, other factors are also important. [Jägerstad: 2012] In one area of the country, these included obesity, high-serum homocysteine levels, low-serum B12 levels, stress, and exposure to fumonisins, which are fungi produced toxins in corn grain. [Suarez: 2012] Genetic mechanisms are also likely involved. [Dupépé: 2017]