evidence: MTHFR status does not change the recommendation that women of childbearing age should take the standard dose of folic acid supplementation to reduce the risk of neural tube defects as per the general population guidelines [...] The MTHFR polymorphism has been associated with many different medical complications. Individuals who are "MTHFR positive" carry one or two copies of variants in the MTHFR gene. However, in general, the following genotypes are unlikely to be of clinical significance: [...] For all individuals, it is important to determine whether medical disorders have been incorrectly attributed to their positive MTHFR status. Referral to a hematologist or maternal–fetal medicine specialist may be needed. And patients should provide their MTHFR genotype status to their physician before starting chemotherapy agents that require folate (e.g., methotrexate).