The so-called low risk of folic acid refers to the abnormal ability of women to metabolize folic acid, but the metabolic ability is not particularly poor, and the risk is low. For women with fertility requirements, they need to increase the dose of folic acid supplementation and also extend the duration of folic acid intake. The dose of folic acid should be increased to 0.8mg per day after pregnancy, and should be taken until after the third trimester. The purpose of folic acid supplementation is to prevent fetal neurovascular malformations by preventing folic acid deficiency in pregnant women.