It helps if you think of them as cycles, with ingredients going in at different points. Of you begin adding MB12, the methionine cycle eill go faster, as long as you have adequate B6, B2, magnesium, potassium, trimethylglycine and methionine.
This will pull more folate (5-MTHF) out of the folate cycle. If you just add folate without the methionine cycle moving well, folate will back up, which is not good.
All of this feeds the production of glutathione, which also requires adequate glycine, glutamine, cysteine, B6 and selenium. Its your body's most powerful antioxidant and is useful in getting rid of all types of toxins. Once it is used, it most be recycled, do you need adequate vitamin C, ALA, etc. to assist in this recycling.
Once the toxins are moving, they head through the transsulfuration pathway, which uses molybdenum and B1. You also need adequate fiber and water intake to drive elimination.
You can guess, or use a test like this to find out what your status is and what you need to do. Click on Sample test to see what it measures. (I do one every 9-12 months.)
https://www.gdx.net/product/nutreval-fmv-nutritional-test-blood-urine
Best wishes