• Folic acid (vitamin B9) is a water–soluble B vitamin.

• It is lost in traditional Indian cooking.

• Folic acid is essential for DNA repair, cell division and normal cellular growth.

• Profound deficiency of folic acid during pregnancy is associated with neural tube defects, such as spina bifida in neonates.

• Deficiency in adults has been associated with megaloblastic anemia and peripheral neuropathy.

• In both men and women, low serum folate levels can increase homocysteine levels, which are correlated with elevated cardiovascular risk.

• Low folic acid levels during pregnancy in women with epilepsy have been associated with fetal malformation and older enzyme–inducing anti-epileptic drugs are known to reduce serum folate levels.

• The risk of having a pregnancy complicated by a major congenital malformation (e.g., neural tube defect) is doubled in epileptic women taking anti-epileptic drugs compared with those women with a history of epilepsy not taking these agents.

• Risk is tripled with anti–epileptic drugs polypharmacy, especially when valproic acid is included.

• Consensus statements recommend 0.4–0.8 mg of folic acid per day in all women planning a pregnancy. Ideally, this should be started at least 1 month prior to pregnancy if possible.

• The guidelines recommend higher daily folic acid doses (4 mg/day) in women with a history of neural tube defects.

• Enzyme–inducing anticonvulsants, such as phenytoin, carbamazepine, primidone and phenobarbital, are known to decrease folate levels, and valproic acid may interfere with folate metabolism.

• Other AEDs such as oxcarbazepine, lamotrigine and zonisamide, do not appear to alter folate levels.

• Because many pregnancies are unplanned, it is recommended that folic acid supplementation be given routinely to all women of childbearing potential at 0.4 mg/day.