Active B12 test [?HoloTC] together with MMA & homocysteine, are recommended by those 'in the know' re. this fascinating B12 biology, including NICE I see, since 2015 !
(AND yet, the NHS continues with only the serum B12, with its known issues . . . ! Hmmm, . . . ! ! ! 😱❓. . . 😑).
Qs:
A) which other closely related tests can be helpful ( - esp in relation to a long term, inflammation-causing, CFS/ME type, illnesses) ?
B) which 'active B12' test bundles ( - with MMA & homocysteine at least) - either postal or in clinic - have pple tried, & been happy with ?
(Have looked at the 'Active B12 extended' pack (postal) available from Superdrug ( - thanks to a post on this forum abt it ! 😊): currently at ~£69, which doesn't seem unreasonable ??!).
Feedback on recent experiences of these tests in the UK wld be v appreciated! Was the Superdrug 'extended active B12' found satisfactory ? Are there better around options for us in England???
Hope to receive some insights shortly . . . - thanks ! 😊
. . . & SADLY, Superdrug seems to have modified its 'extended' test kit v recently, by replacing the MMA & homocysteine, with folate & IF antibodies test ( - which feels like a step in the wrong direction !). 😟 ❓❗A pity, really . . .
I have had the NHS serum B12 test a few times - starting with a 196 ng/L result (range started at 197 ng/L - so didn't have to suffer any longer for lack of B12).
i have also had the active B12 (HoloTC - holotranscobalamin) at least twice, the methylmalonic acid (MMA) six times, the homocysteine test (tHcy) once to my knowledge - all via NHS.
Results were that active B12 was high as was B12 by then - this was taken by haematologists, long after B12 injection treatment frequency given had been increased by GP so unsurprising result.
The first of the MMA tests was requested by GP and came back as raised, lab confirming her concerns that I had functional B12 deficiency. This diagnosis led to introduction of 2 injections a week as the usual regime (6 loading, then an injection every 3 months) had done nothing to stop deterioration. Hence high active B12 results later.
The next 4 MMA tests were taken by haematologists and all still raised despite frequency of injections.
The final MMA test, three years after the first, showed that the frequent B12 injections were working - as it had finally dropped into mid-range. This was taken by Adult Inherited Metabolic Diseases team (who were looking at my DNA too).
The homocysteine test was taken by haematologists and the report to GP was that it was "normal".
The only test I have ever had privately was a postal kit to check thyroid - since NHS only generally does TSH and FT4 and I wanted the full range including 2 autoimmune thyroid condition tests. I needed assistance here with interpreting the online test results - Marz gave very helpful advice on what to look out for and what would be ideal. This test request was due to two of my sisters having Grave's disease. I think around £60 for 6 tests - seemed fair.
As you can see, a good determined GP can get much done, including appointment referrals to secondary care for further testing not so easily obtained at primary care level.
If you are already having B12 injections, serum B12 and active B12 are likely to be high. With frequent injections, very high. MMA however should have dropped into range, even if previously high, certainly once the loading injections have been given. If not - the likely causes are renal problems, SIBO - and functional B12 deficiency, if tests have eliminated the first two as causes.
NOTE: If you have low B12 and are being tested for pernicious anaemia (PA)specifically, the usual test used is IFab (intrinsic factor antibody) test - but this will be positive in only about 50% of those with PA. Not all GPs are aware of this fact, although their advisory bodies are, and this can mean that a single negative test result can be misinterpreted to mean that you do not have PA. So there is no "PA test" as such. Have a read of NICE guidelines if your GP uses this result erroneously to stop your injections.
Ensuring that people here are aware of how the results can be used to stop vital injections, by GPs misinterpreting the meaning of the result given.
Easy, out of desperation, just to say "yes" to everything. Also difficult to absorb masses of important information when cognitive or memory issues and anxiety keep blanking it out !
[ I had to refuse antidepressants three times initially as I did not recognise my condition as depression. Had I agreed to this treatment, it might well have prevented any further investigations. ]
. . . SADLY the known limitation of the serum B12 test - including as critiqued by NICE, 2015 - in a 44 page paper - are n⛔t still widely enough recognised; its left to US to find these points of reasonable clinical practice, . . . & bring them to the attention of our too busy Drs ! So be it . . . !!❗ We're helping them, . . . to help us, . . . & others, too ! 😊
. . . interesting that 'antidepressants' increase levels of various neurotransmitters, like noradrenaline & serotonin. B12 is more specifically ( - among many other things ... ?!) said to reduce levels of homocysteine & MMA in the body/blood, . . . & importantly in the CNS, for all those 'neuro' symptoms.
Higher serotonin & dopamine levels are said to result from increasing the body's ( - & therefore the CNS' ) B12 amounts, . . . in the case of many chronic illnesses to what would really be "supra-physiologic doses" in the healthy population, . . . surely ??!**
Sid 😑
Sat 13 May 2023* . . . - one CALM step at a ⏳❗😑
(* - 40 years 'already' since Fri 13 May 1983 . . . right on ⏳❗ Know one thing I did then, . . . & Y🍥U . . . dear reader ??❓ 😊 ).
** - added as an afterthought, the following day. 😑
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B12 testing 
IFA negative, Low Active B12 - advice please. 
