I know that many people don't have their I.F. tested, because of its unreliability, or it comes back negative when it shouldn't, but I wondered how many people have tested positive.
It's purely out of curiosity. Mine tested positive, which I was very relieved about, as it would have been a struggle to get my G.P. to treat me without it, as my serum B12 was 'normal' at 250 and all of my symptoms were in my head apparently.