I didn't realize betaine was a methyl donor, which explains a few things for me. I have some gas issues after methyl group supplements like methyl folate and methyl cobalamin
I was just reading about vinegar, and I did try vinegar after two of my meals where I also took vitamins. I noticed I felt almost hyper after them. So possibly the vinegar helped me break down the food and vitamins better.
But yuck, vinegar straight is not good. So I'm going to order some tablets instead. lol