1. Prevent anemia in pregnant women, whose bodies need folic acid to make normal red blood cells. Survey shows that the prevalence of anemia among Chinese women of childbearing age is 20.6 percent. Insufficient intake of folic acid may also make pregnant women anemic. 2, reduce the risk of birth defects, after 13 years of research in the “Sino-US Neural Tube Deformity Prevention Cooperation Project”, 250,000 cases of evidence-based medicine confirmed that women of childbearing age who take 0.4mg of folic acid daily from the time they prepare for pregnancy can reduce the incidence of fetal neural tube malformation by 85%, reduce the incidence of fetal cleft lip and palate by 50%, and reduce the incidence of congenital heart disease by 35%. The incidence of congenital heart disease can be reduced by 35%, and the incidence of major neonatal malformations can be reduced by 15% and the neonatal mortality rate can be reduced by 20%. 3. In addition to fetal growth and development, the maternal blood volume, breast and placenta development make the demand of folic acid increase greatly in the middle and late pregnancy. Insufficient folic acid makes pregnant women prone to placental abruption, gestational hypertension syndrome and megaloblastic anemia; fetuses are prone to intrauterine growth retardation, premature birth and low birth weight, and the growth and intellectual development of such fetuses will be affected after birth.