We didn't try to get to any quantity. We tried to get better.
If you are worried about your cognitive ability, you could ask a friend/volunteer/student/family member to help you. If you haven't yet, read that start low and go slow document of caledonia's.
Why are you aiming for methylation? Have you done Freddd's party trick and tucked a b12 into your gums and had a response?
In our case, we tried
this low-slow approach, but the nausea from the adoB12 was so extreme we had to start with the a little mB12 instead, and got a brighter, more colourful view of the world from it a few hours later.We'd also been doing all the other supplementy things for a year or more. We take methylfolate only in response to need, and not much of that on most days.
Some people I've read here could cope with only a crumb of mb12 before getting an extreme reaction. A reaction can also come hours afterwards, by the way.
Everyone reacts so differently to this thing. It's not a toy.