Hi I'm new here but would like a sanity check or advice if possible. I was diagnosed with B12 deficiency 5 years ago (the same week I was diagnosed with breast Cancer) I was 39. I have received 12 weekly B12 injections every since and often become symptomatic a week or so before I'm due one however I have really really struggled the last few weeks with extreme tiredness, dizzy spells, headaches, nausea etc etc. I put it down to workload and the amount of miles I'm driving each week however I am now convinced it's my pernicious anaemia. I saw my GP this morning who is not convinced it's commented to B12 as my next dose is not due til end April and is thinking more along the lines of diabetes or thyroid. Does anyone have any advice? She has done bloods so I will hopefully find out next week but I must admit I've never researched by B12 as I've just accepted what I've been told.