Folic acid is a water-soluble vitamin. 5mg of folic acid is taken orally all the time during preparation for pregnancy and will be excreted on its own in case of overdose, but all medications should be used in accordance with medical advice. The first 3 months of pregnancy preparation and the first 3 months of pregnancy are generally recommended to take 0.4mg~0.8mg of oral folic acid to prevent the occurrence of fetal neural tube malformation. However, for repeated miscarriages or other cases, doctors recommend taking 2.5mg~5.0mg of folic acid orally every day, which is a water-soluble vitamin, such as excess can be discharged on its own, and there is generally no need to worry about the problem of overdose, but all the medications should be used in accordance with the doctor’s instructions, and should not be added to the amount of unauthorized use. Folic acid can not only prevent fetal neural tube malformation, but also promote fetal brain development, in addition, the lack of folic acid can also cause megaloblastic anemia, in addition to folic acid preparations, folic acid exists in a variety of green vegetables, fresh fruits, pig liver, beef liver, mutton and other foods, should be moderate to increase the amount of food.