Can I ask what your low levels were? I have just had a full blood count done and my MHC count is abnormal - I have looked back at all my previous blood tests and they are all the same - every single one shows this as abnormal but because it is always abnormal the gp has marked the results as acceptable?!
OMG, I've just come across this. I had to check that it wasn't me who'd written this in my sleep!
I've had all symptoms of VitB12 deficiency for some time now, but getting much worse in the last 4 months. After a very bad turn, I asked my GP for a blood test and result came back that B12 serum was normal (400 so right in the middle of the range) but my MHC was very high (34.8). My GP dismissed it as all my other results were fine and like yours, it came back as acceptable.
Unfortunately, I continued to deteriorate and my anxiety was off the roof which of course led to all my symptoms being put down to this. I felt so helpless, I started to do my own research and ended up on the Penicious Anemia website and learned that the Serum B12 test was a very unreliable test anyway and in desperation, I decide to order some intravenous B12 online via the company suggested on their forum.
I started the injections myself as per NICE guidance. The first two saw my symptoms getting worse which led me to the GP again, a different one who did take me more seriously, but again wouldn't consider B12 deficiency because of the serum level, but ordered further tests (to check proteins, thankfully, these all came back fine). However, I started to really feel the difference after my 5th injection and suddenly, it's as if the fog was lifted and for the first time in many months, I got a hint a how I used to feel. You get so used to feeling dreadful, you forget what it's like to be half normal.
My 6th and last injection was on Monday and I felt my best ever on Tuesday and Wednesday and then the symptoms started to come back on Thursday, were full on again yesterday and woke up this morning back to how I felt before, drained, weak, horrible tinnitus, head fog, bad sleeping and yes, anxiety which had completely disappeared.
I've decided to give myself another injection this morning and will do so again every other day for the rest of the week. If I start to feel better again, then there will be no doubt in my mind, and I will be back to the GP asking to be referred.
Both the GPs I saw said that I couldn't be deficient because of the serum results. Neither knew much about VitB12 deficiency, let alone that the test is not reliable in many cases.