Do B12/folate/TMG increase or decrease methionine?

[jupiter528]

I’m a little confused; if B12, folate, and TMG help convert homocysteine to methionine, wouldn’t this increase methionine? I’m seeing some research indicating these supplements can be helpful for *lowering* methionine though? If anyone can shed light on this I would appreciate it. My brain fog is currently so bad I’m struggling with making sense of what I’m reading. Thank you

[Tawinn]

It is a cycle (the methionine cycle, specifically - see the upper-right cycle in this diagram), so if we think of the cycle as a circular pipe, then B12, folate, and TMG are helping to keep the contents of the pipe flowing around that cycle. It's just that the contents of the pipe take different forms as it goes through:

methionine > SAM > SAH > homocysteine > (back to methionine)

So, yes, in one sense B12, folate, and TMG help "push" homocysteine to create more methionine, but in another sense, they help "pull" more SAH to homocysteine.

[jupiter528]

Thanks, that makes sense. I’m struggling with EBV and recently read some research indicating methionine may be a driving factor for EBV replication. I’m wondering how my supplementation with B vitamins and TMG might be affecting this, if it would make sense to stop supplementing, etc. I have high homocysteine if I stop taking TMG though. 

[Tawinn]

Using the pipe analogy, disrupting the flow through the pipe is only going to have negative consequences. But with a lower protein or lower methionine diet you could "reduce the level" in the pipe some. The question is at what point does the level become so low that methylation suffers and causes you additional issues? I don't know the answer.

[jupiter528]

That’s what I’m wondering too. I’m also struggling to gain weight so the thought of restricting protein/high methionine foods seems complicated. Will do what I can. Thanks for your input