Like so many others. I am finding it nearly impossible to get past my GP with regards to B12 deficiency because my serum levels are OK.
I understand how it can be difficult for some of us to get B12 from our blood. But how does the B12 get from the blood into the cells? If there is a problem with that latter stage, it would explain why many of us with PA symptoms have higher B12 serum levels.
All I know is that when I've had B12 injections (twice) I've felt better than at any other time in my life. That apparently is not a good enough reason to prescribe injection.