Results from a 2021 prospective intervention study showed that supplementing women with different MTHFR gene mutations with multivitamins containing 0.8 mg of folic acid significantly increased serum folate levels, reduced homocysteine (Hcy) levels, and may help lower the risk of neural tube defects (NTDs) in offspring (Kuroda et al., 2021). Here, MTHFR is linked to isolated spina bifida.