The total amount of folic acid eaten by the elderly is recommended to be within 15mg per day. Folic acid is one of the nutrients of the body and it is necessary for the elderly to take folic acid supplements. Folic acid is able to fight against atherosclerosis and is one of the drugs used to treat H-type hypertension. Folic acid can also be used to treat megaloblastic anemia when taken together with vitamin B12. However, elderly people should take folic acid in controlled doses to avoid side effects such as nausea, vomiting, bloating, anorexia, and neurological impairment, while folic acid can also affect the efficacy of antiepileptic drugs when taken by patients with epilepsy. In addition, large doses of folic acid can also affect the absorption of trace elements such as zinc. Therefore, elderly people should be careful not to take too large a dose of folic acid, especially those with liver or kidney insufficiency, and should take small doses.