Right so I have just had my latest serum B12 result which I was hoping would now be on the range considered deficient so I could get my injections reinstated. Unfortunately it's not it's 501 ng/l, but it's gone down considerably since they last tested it. I've now been about four months since my last injection, and I feel worse than I have for the last year or so, sleeping all the time, numbness bad, shortness of breath etc.
I know others have said that the serum B12 level isn't useful if on injections, but can anyone explain to me how it works with regards to the functional B12 level vs serum b12? It looks like the oral supplements aren't sustaining the serum b12 level at the level it was after my last injection, but it still has a fair way to go before it reaches deficienct levels again. So have I understood this correctly that B12 is stored but that doesn't mean that all of this B12 is available for use? Or is it just that B12 is no longer the problem and something else is causing my symptoms? I'm pretty confused to be honest and kind of fed up of not feeling great. I intend to start self injecting, I guess I can't do any harm by doing so, and hopefully it will help. Anyway any advice would be appreciated thanks.