Folic acid in the size of 0.4mg/tablet should be taken during pregnancy preparation, and the specific dosage should follow the doctor’s instructions. Folic acid is a kind of coenzyme substance that can play an important role in the process of cellular DNA synthesis, and it is generally recommended that women who are preparing for pregnancy should take folic acid tablets orally, so as to prevent the lack of folic acid in the body from affecting the development of the fetus’s nervous system. Clinically, it is often recommended that women taking folic acid tablets with a specification of 0.4mg/tablet should take them from the beginning of pregnancy to 3 months after pregnancy. Note that folic acid tablets should be contraindicated in people who are allergic to the product, and long-term use of the drug may lead to loss of appetite, nausea, abdominal distension and other gastrointestinal discomforts and adverse reactions. The specific use of folic acid should be carried out under the guidance of a specialist physician.