Folic acid has little effect on blood sugar levels in diabetics, so patients can take folic acid for a long time if their condition requires it. Folic acid is an anti-anemia drug. It is used for folic acid deficiency caused by various reasons and megaloblastic anemia caused by folic acid deficiency, preventive medicine for pregnant and lactating women, and folic acid deficiency caused by chronic hemolytic anemia. Folic acid adverse reactions are rare, rare allergic reactions. Gastrointestinal symptoms such as fear of food, nausea, and abdominal distension may occur with prolonged use of the drug. When large amounts of folic acid are taken, it can make the urine yellow. The precautions of folic acid are not to be injected intravenously, and it is generally not used for maintenance therapy, except for patients with malabsorption, and oral administration of large doses of folic acid can affect the absorption of zinc, a micronutrient. It should be noted that megaloblastic anemia caused by vitamin B12 deficiency cannot be treated with folic acid alone. Folic acid is contraindicated in patients who are allergic to folic acid. Folic acid has no effect on the patient’s blood sugar, but long-term use of folic acid needs to be taken under the guidance of a doctor, can not be taken on their own, in order to prevent improper use, resulting in serious adverse reactions.