The average person taking folic acid on his or her own for a long period of time has side effects and may have health consequences, as it is not necessary to take folic acid for a long period of time in most cases, and may even show signs of toxicity if taken in excess. Folic acid is a water-soluble vitamin (B9) that is essential for the growth and reproduction of human cells and can be used to treat megaloblastic anemia caused by folic acid deficiency, to reduce the risk of fetal malformation to some extent, or folic acid deficiency caused by chronic hemolytic anemia, etc. In addition folic acid has some nerve-nourishing effects and can improve the quality of sleep. Folic acid can also lead to a lower risk of stroke in patients with hypertension and prevent and reduce the risk of cardiovascular disease. It is generally not recommended to take folic acid for a long period of time without examination, because the average person who takes folic acid for a long period of time or in excess may cause symptoms such as numbness, tingling, weakness, fatigue, nausea, anorexia, etc. It may also affect the absorption of zinc, and these conditions should be promptly seen by a hospital. In addition, folic acid is not recommended for patients who are allergic to folic acid, have abnormal liver and kidney functions and are taking anticonvulsant drugs such as phenytoin sodium. During the preparation and pregnancy period, women can choose whether they need to take folic acid for a long period of time based on the results of the tests and after talking with their doctors. Generally speaking, women can take folic acid 3 months in advance during the preparation period, and supplementation under the guidance of a doctor can reduce the possibility of fetal malformations. For the general population, dietary supplementation is sufficient and can be supplemented with green leafy vegetables and other foods.