“Taking greater than 1,000 micrograms (1 milligrams) of folic acid is not recommended unless a patient has a history of a child with a neural tube defect (spina bifida),” advises Lipinski. While autism is multifactorial and therefore difficult to make a direct correlation to increased folic acid intake, according to Rikki Baldwin, MD, a board-certified ob-gyn at Memorial Hermann Health System, research indicates prenatal vitamins exceeding 1,000 micrograms of folic acid could be related to an increase in the risk of autism.