This enzyme plays a role in processing amino acids, the building blocks of proteins. L-5-Methylfolate reductase is important for a chemical reaction involving the vitamin folate (also called vitamin B9). Specifically, this enzyme converts a form of folate called 5,10-methylenetetrahydrofolate to a different form of folate called 5-methyltetrahydrofolate.
This is the primary form of L-5-Methylfolate found in blood, and is necessary for the multistep process that converts the amino acid homocysteine to another amino acid, methionine. The body uses methionine to make proteins and other important compounds.
The decrease in the level of L-5-Methylfolate is linked with different autoimmune diseases such as autism. Our body needs enough MTHFR to perform essential functions, and its increase or decrease is also linked to heart problems, so you have to be careful in this matter.