It is recommended that women start taking folic acid in the first trimester of pregnancy, which can last throughout the entire pregnancy and even up to breastfeeding. Folic acid is a water-soluble vitamin that is one of the essential nutrients for the body. The main function of folic acid is to strengthen the body’s immunity and participate in blood production. Taking folic acid during pregnancy can prevent the fetus from developing neural tube malformations, such as hydrocephalus and spina bifida. The synthesis of the baby’s DNA in the middle and late stages of pregnancy, and the increase in placenta, maternal tissues and red blood cells all increase the need for folic acid. So even though the baby’s nervous system is well developed in early pregnancy, a deficiency of folic acid in mid to late pregnancy can still cause diseases such as megaloblastic anemia. It is therefore recommended to take folic acid supplements throughout pregnancy. There is no special requirement for the time of taking folic acid orally every day, it is best to choose a fixed time to take it every day after meals. Besides taking folic acid tablets, pregnant women can also get folic acid from food, such as green leafy vegetables and fruits.