The mthfr gene test is mainly used to detect whether the folate metabolism level is normal or not, and often has three kinds of results: CC, CT and TT. The mthfr gene test is methylenetetrahydrofolate reductase test, which can be used to determine how much exogenous folic acid needs to be supplemented. The test results can be categorized into CC (wild-type), CT (heterozygous mutant), and TT (pure mutant), which usually corresponds to low-risk, medium-risk, and high-risk. 1. CC type: It means that folic acid metabolism is normal, and there is no need for additional supplementation through food. 2. CT type: indicates that the activity of mthfr enzyme is about 65%, and additional folic acid supplementation is required along with daily food supplementation. 3. TT type: the activity of the enzyme is only about 30%, indicating that the patient has poor absorption and metabolism of folic acid and needs to use folic acid supplements. Currently, the mthfr gene test is crucial for women during pregnancy and gestation. Studies have confirmed that folic acid deficiency has a clear impact on neonatal defects such as neural tube malformations, Down’s syndrome, cleft lip and palate, and increases the risk of complications during pregnancy, such as gestational hypertension. Patients who are deficient in folic acid through the mthfr gene test should pay great attention to taking measures such as a balanced diet and the rational use of folic acid supplements under the guidance of a physician to accurately replenish the required dose of folic acid.