Folic acid during pregnancy has been shown to reduce ... with no evidence of negative effects at higher doses." Kimford J. Meador, MD, PhD, study author of Stanford University in Palo Alto ...

but the best dose of folic acid is unknown," said study author Kimford J. Meador, MD, Ph.D., of Stanford University in Palo Alto, California, and a Fellow of the American Academy of Neurology.