Folic acid should be taken by all women of childbearing age. The easiest way is to take a prenatal vitamin or multivitamin for women with 0.4 to 1 mg of folic acid. These are available over the counter and should be started at least a month PRIOR to getting pregnant. Three months before pregnancy is even better. Higher doses of folic acid are needed in women with epilepsy, taking the medications tegretol or valproic acid, obesity, uncontrolled diabetes, or personal or family history of open neural tube defects. Prescription for regular dose Pregvit or high dose Pregvit are available from a doctor.