Folic acid is a water-soluble B vitamin that is abundantly stored in green leafy vegetables, fruits and animal livers. Folic acid is involved in the whole process of human metabolism and is an essential vitamin for the synthesis of DNA, an important substance in the human body. Its deficiency can lead to fetal neural tube malformations, in addition to an increased rate of malformations in the eyes, mouth and lips, palate, gastrointestinal tract, cardiovascular, kidney, bones and other organs. A daily dose of O,4 mg of folic acid supplements between the first month of pregnancy and the second trimester of pregnancy can prevent the occurrence of most neural tube malformations in the fetus. It is worth mentioning that women should take folic acid under the guidance of a doctor, and in addition, the following points should be noted The purpose of emphasizing the need to start taking folic acid before pregnancy is to maintain a top level of folic acid in a woman’s body to ensure a better nutritional status of folic acid in the early embryo. According to research, it takes 4 weeks after a woman takes folic acid for the folic acid deficiency in her body to be corrected. In this way, during the sensitive period of fetal neural tube formation in early pregnancy, sufficient folic acid can meet the needs of neurological development, and it should be taken consistently during the sensitive period in the first trimester after pregnancy to achieve the best preventive effect. 2.Women in the low incidence area of neural tube malformation in China also need to supplement folic acid. The incidence of neural tube abnormality in China is higher in the north than in the south, and higher in rural than in urban areas. Therefore, some people think that women in low incidence areas can not take folic acid when they are pregnant, the existence of this understanding is likely to become a hidden danger of the birth of neural tube abnormality children. According to the survey, a significant proportion of women of childbearing age in the low incidence areas are still deficient in folic acid. Therefore, women in low incidence areas should never take it lightly before pregnancy. 3.Does taking folic acid supplements guarantee that no neural tube abnormalities will be born? Folic acid supplements are taken to prevent neural tube abnormalities caused by folic acid deficiency in pregnant women. Folic acid deficiency is the main cause of neural tube abnormalities, but it is not the only cause. There are also family genetic factors and other environmental factors that can cause neural tube abnormalities, and there is no definite way to prevent them. According to domestic and foreign research, taking folic acid supplements can prevent 80% of neural tube abnormalities born. 4, do not use “folic acid tablets” instead of “small doses of folic acid supplements”. Folic acid supplements contain only 0.4 mg of folic acid per tablet, which is the only preventive medicine approved by the state (the trade name is “Silien”). There is a kind of “folic acid tablet” in the market for treating anemia, which contains 5 mg of folic acid per tablet, equivalent to 12.5 times of “Silien” tablet. Pregnant women should not take such high doses of folic acid tablets in early pregnancy, because long-term high doses of folic acid tablets can have adverse effects on the pregnant woman and the fetus. Therefore, pregnant women are reminded to follow the guidance of their doctors and health care providers and not to take or buy drugs indiscriminately on their own.