Folic acid is an important B vitamin that women take during pregnancy primarily to prevent neural tube abnormalities, while men take folic acid primarily to lower homocysteine. Increased homocysteine can lead to atherosclerosis, which in turn can lead to ischemic cardiovascular disease. Homocysteine requires folic acid, vitamin B12 and vitamin B6 in the metabolic process, and deficiencies in all three vitamins can lead to hyperhomocysteinemia, so taking folic acid tablets is mainly to lower homocysteine and subsequently prevent cardiovascular diseases. The human body needs 0.8mg of folic acid per day, and 1 tablet per day is sufficient for folic acid supplementation. In addition, folic acid supplementation needs to be taken for a long time, if taken for a short time it may cause homocysteine to increase again, and it is recommended to take folic acid orally for more than 3 years.