As a vitamin, folic acid is important for producing blood cells and promoting normal nerve development. Pregnant women who are deficient in folic acid in early pregnancy are prone to congenital malformations in the fetus. The most common of these are neural tube disorders, which mainly affect the normal development of the brain and spinal cord; for example, the familiar spina bifida is a common malformation. Other common malformations include cleft lip, cleft palate, heart and genitourinary malformations. The “U.S.-China Collaborative Project for the Prevention of Neural Tube Deformities” has tested folic acid levels in nearly 250,000 women of childbearing age in 30 cities and counties in Hebei, Shanxi, Jiangsu and Zhejiang provinces, and has finally proven with a large sample of data that a small daily dose of 0.4 mg of folic acid supplementation before and after pregnancy can indeed It has been shown that a small dose of 0.4 mg of folic acid supplementation before and after pregnancy can effectively reduce the incidence of birth defects, especially neural tube abnormalities. Therefore, women who are planning to become pregnant should take folic acid supplements earlier, usually three months in advance. If you take folic acid supplements when you find out you are already pregnant, it will probably be too late. For women with epilepsy, folic acid supplementation doses may have to be larger than normal for women, especially if they are taking phenytoin sodium, carbamazepine or stupid barbiturates, as these medications can interfere with the absorption of folic acid. Increased folic acid supplementation is also recommended for patients taking multiple antiepileptic drugs or taking greater than 1000 mg of valproic acid per day. If there have been cases of neural tube abnormalities in previous births, the folic acid supplementation dose should also be increased accordingly. For patients taking both phenytoin sodium and larger doses of folic acid, the blood levels of phenytoin sodium should be checked regularly, as high doses of folic acid may reduce the concentration of phenytoin sodium, which may lead to worsening seizures. Therefore, women with epilepsy should visit the hospital on time and adjust the dosage of antiepileptic drugs and folic acid according to their condition.