FredddLet's look at the half lifes then. While 99% of the B12s are out of the body in a day, it takes about 3 days for b12 deficiency symptoms to start getting worse after a number of doses. The AdoCbl has a 99% loss from the bloodstram in 24 hours BUT once it is in the mitochondria it appears closer to 71 day tissue halflife. The l-methylfolate has about 3 hours halflife. I go into folate insufficiency simply by missing a single dose or having it blocked by potassium.
Thanks @Mary me too. I've been taking together for some years, and more recently taking methylfolate sublingually, which I noticed was an improvement -- but then I was wondering if the block only occurred when taken together orally.