I have now had all the tests that Haematology and Neurology requested:
Nerve testing in hands and feet - everything fine
Active B12 - above 128pmol/L
Homocysteine levels - normal
MMA and B12 blood tests prior to and post monthly B12 injection
Repeat Folate test
MRI brain scan
Genetic testing (blood) for one carbon metabolism and cobalamin disorders
The letter to my GP and Haematology from Neurology suggested possible riboflavin &/or co-enzyme Q10* deficiency- although he had admitted to me that he did not know much about B12 deficiency *aren't there any tests for these?
The latest letter to my GP from Haematology said the active B12 test result suggested "adequate B12 replenishment", although MMA "slightly elevated (MMA 364nmol/L)" and homocysteine levels normal. She had discussed raised MMA with a colleague who said that MMA levels could have other causes/ may be normal for my age. (I'm 59)
"Some laboratories use an upper limit of normal value of above 450nmol/L as an indication of B12 insufficiency." SIBO was then suggested and a breath test* to diagnose. *Not sure who would do this? Haematologist? Not an NHS test?
"Her MMA levels are unlikely to reflect functional B12 deficiency whilst on B12 injections" (which is apparently why I was tested just before and just after injection)
I have not had the MRI results or the B12, MMA, Folate blood tests, or genetics lab feedback and believe that this will all be discussed at 3rd appointment in mid-August. Despite still struggling with symptoms, no increase to injections, as they are "unable to recommend B12 treatment at intervals of any greater frequency than that stated in the BNF" (so probably would prefer to decrease monthly injections)
Trouble is, my certificate runs out in September, when I will have been off sick for a whole year, and no effective course of treatment has yet been established. Nothing has changed. I am currently unfit to do any job due to cognitive problems, very low energy levels etc.etc.etc. Time is running out for me, and I'm almost certain that the next Haematology appointment will be my last. Not sure how to address all these issues in what is likely to be a brief run-through of results, what to ask for or how to continue. Two weeks after that appointment, I'm expected back at work. Or leave.
Any help or advice welcome.