Assessing the risk of excess folic acid intake

It is well established that folic acid supplementation can significantly reduce the risk of birth defects, including neural tube defects like spina bifida, the most common birth defect of the central nervous system and the second most common of all structural birth defects. More than 80 nations, including the U.S. 25 years ago, have established mandated folic acid food fortification programs, which have been successful.