I'm b12 deficient first diagnosed in 2012 by a reluctant GP. He ordered an intrinsic antibody test which was 2.4 Southend lab range 0-6. So this was normal. I've had treatment and b12 comes and goes according to my levels. However it's now 2016 and I've revisited this as I believe this is auto immune and PA. docs not bothered as treatment is the same, I am bothered tho! Why are the ranges so different from one lab to another, as 2.4 would be a positive for antibodies according to other labs. All doc will say is different methods.... But that is a big difference in range to my mind? I'm now having a paretial cells antibody test after mega insistence some 4 years later... I feel like they have tried to insinuate it's just poor diet and I'm unhappy and feel not properly diagnosed?!