Folic acid according to the normal dose of consumption generally has no effect on the kidneys, if it is a long-term high dose may have harmful effects on the kidneys. Folic acid is a kind of B vitamins, clinically mainly used for the treatment of folic acid deficiency and some types of anemia caused by folic acid deficiency; clinically can follow the doctor’s instructions according to the amount of folic acid can be effective in the prevention of neural tube malformation, megaloblastic anemia and other diseases, the kidneys are not harmful. As drugs are generally excreted through the kidneys, if patients take large doses for a long time, it may affect the excretory function of the kidneys; patients taking large doses of folic acid for a long time may have nausea, loss of appetite and other gastrointestinal symptoms, and in severe cases, it may cause changes in renal function, which may lead to renal diseases, so you need to check the renal function regularly during the period of taking folic acid. Folic acid should be taken in accordance with medical advice, can not blindly increase or decrease the dose and time of the drug, so as not to affect the health of the body.