MTHFR stands for methylenetetrahydrofolate reductase, which is an enzyme involved in the metabolism of folate by catalyzing 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate.3 The gene which codes for the reductase enzyme is a polymorphic gene with more than 50 variants known. The most notable mutation is a missense mutation at codon 667. Individuals with the wildtype homozygous CC genotype for the gene maintain the ability to metabolize folate to the usable form, L-5-methyltetrahydrofolate. Some individuals may be heterozygous CT, while others may be homozygous TT for the gene. The substitution from C->T changes the amino acid made, making valine instead of alanine which impairs with the resulting MTHFR activity.3 Therefore, those individuals with the CC genotype are able to metabolize folate much better, compared to those with the T mutation. Since folate is paramount in the neural tube closure and prevention of neural tube defects in the developing fetus, a variant (677C->T) in the MTHFR gene is the most established genetic risk factor for neural tube defects (NTDs).3 In addition, proper folate metabolism is vital in red blood cell regeneration which is important in pregnant women to prevent iron deficiency as their blood volume increases. Quatrefolic® – (6s)-5-methyltetrahydrofolate – is the already bioavailable form of folate, which means it does not require MTHFR for metabolism and absorption. This is advantageous because women with the MTHFR genetic variants may enjoy the absorbable power of Quatrefolic®.