Women 40 years old can eat folic acid, but non-essential, do not need to take additional folic acid, pregnancy, megaloblastic anemia and other cases, under the guidance of the doctor to eat folic acid. Folic acid is a kind of B vitamins, woman 40 years old body aspects are not abnormal, do not need to take extra folic acid, daily life food contains folic acid, such as lentils, oranges, broccoli, etc., the normal intake of food to meet the body’s folic acid needs. If you are 40 years old and have a pregnancy, you can take folic acid tablets to prevent fetal neural tube malformations, usually taken three months before pregnancy, folic acid deficiency throughout the pregnancy can eat folic acid. Woman 40 years old with megaloblastic anemia, is the body lack of folic acid and (or) vitamin B12 caused by this situation can be under the guidance of the doctor to take folic acid tablets to treat the disease. There is chronic hemolytic anemia caused by folic acid deficiency, you can also take folic acid. Folic acid is prohibited for those who are allergic to folic acid drugs, and folic acid alone is prohibited for megaloblastic anemia caused by vitamin B12 deficiency, and folic acid should be used with caution for those with abnormal liver or kidney function, alcoholism, and those who are taking anticonvulsant or antiepileptic drugs. It is recommended to take folic acid under the guidance of a doctor, overdose may appear numbness or tingling, pain in the mouth or tongue, fatigue, lack of concentration and other adverse reactions, there are abnormalities in time to seek medical attention.