Folic acid can be taken during menstruation. If a woman is preparing for pregnancy, it is recommended that folic acid can be taken during the first trimester of pregnancy and can be taken continuously, without stopping in the middle of the menstrual period, and only 0.4 mg per day is required, as well as during the first trimester after pregnancy. If the patient’s folic acid metabolism is high or medium-high risk, it can be taken throughout pregnancy and the dose can be increased to 0.8 mg. If the patient uses folic acid mainly to treat anemia caused by folic acid deficiency, it is not necessary to stop taking it during menstruation and it should be taken until the symptoms of anemia are improved. However, the decision must be based on the cause of the disease and treat the cause completely, otherwise there is a possibility that the anemia may reappear if the cause persists after stopping the medication.