I can find no main stream medical papers that even use it. Methylation is used in relationship to dna.
What is the methylation cycle and how doe... - Cure Parkinson's
What is the methylation cycle and how does Thiamine affect it.
suzycohen.com/articles/meth...
I found this person's explanation to be fairly easy to understand.
The term "methylation" has been subverted by internet quacks and is now being used out of context to describe theoretical improvements in body chemistry. It is the same type of nonsense that you find on the internet about changing the alkalinity of your body. The article above is about as scientific based as my daughter's belief that "baby carrots" are made by dissolving big carrots in chlorine.
"... my daughter's belief that "baby carrots" are made by dissolving big carrots in chlorine."
Aren't they ?
Methyl group recycling is related to the Krebs cycle (aka citric acid cycle).
en.m.wikipedia.org/wiki/Cit...
ncbi.nlm.nih.gov/m/pubmed/1...
If you want to understand the methylation cycle I suggest you visit the Pernicious Anaemia/ B12 forum on this site where there are people who understand it. Dopamine pathways intersect with the methlation cycle so it is possible that improvements could be effected i. functional aspects of PD at aome point in the future. All of this is theoretical wrt PD, however wrt b12 deficiency there is science to back it up. Interestingly ling term deficiency can produce conditions that mimic PD. There are studies out there that indicate that PWP elders are often deficient in b12 and folate and that correcting the deficiencies brings improvement. Anyway the people to talk to are the b12 def guys, the methylation cycle and uptake of various types of cobalomin dirrectly affect them.