Methylation is a process that involves moving a methyl group (a carbon plus three hydrogens, CH3) to another molecule. For example, methylation occurs in the cell nucleus where it is involved in turning on or off genes for transcription. It is also involved in converting numerous substances into their active version (e.g. melatonin) or into their inactive version. It is a process that is taking place billions of times per second throughout your body.
These methyl groups are formed, in part, through the conversion of folate to methyl folate using the gene MTHFR along with vitamin B12. The other way you can produce methyl groups is from choline.
The first stop in learning about your methylation cycle gene variants is:
Check Your Genetic Data for MTHFR.