I started having small fiber neuropathy several years ago after being exposed to Lyme and Mold. Spent a lot of time treating with herbs to put both into remission, but I still deal with the small fiber neuropathy in my feet, my lips have a blue tinge to them as to the moons on my thumb nails.
I just went through more testing than I can ever imagine and while my serum B12 level has always been high at around 2000, I tested positive for pernicious anemia and have been told I need hydroxy injections on a daily basis.
Why would my serum levels be so high and I have pernicious anemia? When doctor hypothesized that the B12 was floating around in my blood, but not actually being absorbed because I lackintrinsic factor.
I do not have MTHFR, but I have a lot of other genetic snips like COMT, CBS and other mutations that make it impossible for me to take methyl related vitamins.
If I take these B12 hydroxycobalamine injections, will it make my B12 levels go up even higher and cause more problems? Or will it help stop the small fiber neuropathy, the blue lips and thumbnails?
this is all been so confusing and happening so fast.
any insight would be greatly appreciated
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SunriseDaily
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Might be worth researching "Functional B12 deficiency" and "Paradoxical B12 deficiency"
This is where there is plenty of B12 in the blood but it's not getting to where it's needed in the cells.
MMA, homocysteine and Active B12 (holotranscobalamin) tests may help to diagnose functional B12 deficiency.
I've read about cases of people having symptoms of B12 deficiency with serum B12 results above the normal range.
Search online for "high B12 with deficiency symptoms"
High B12 levels without taking B12 supplements and without having B12 injections can sometimes be associated with a serious health condition.
I'd expect a doctor to check liver and kidney function and to order full blood count (complete blood count) in someone who has high serum B12 without taking B12 supplements/B12 injections.
A few links that might be useful
PAS (Pernicious Anaemia Society) is based in UK but has members across the world.
PAS membership is separate to membership of this forum.
The doctor could well be right. If your B12 is pooling uselessly in your bloodstream, then one would suppose that the transporting methylmalonic acid (MMA) - which forms the link with B12 to ensure it arrives at necessary cells and tissues - would be doing the same.
So, if your doctor wanted to check that, a serum MMA test could provide an answer.
Despite being given B12 injections for B12 deficiency, I was not responding and symptoms were getting worse. My MMA was found to be raised which gave me a functional B12 diagnosis, as my GP suspected. Despite then getting frequent B12 injections (2 per week), MMA remained raised for three years.
Hi Cherylclaire - bit curious about MMA being seen as a B12 transporter - I thought that was transcobolamin. MMA is a compound formed when some amino acids and fatty acids are being broken down and helps to mediate the process that produces adenosylcobalamin inside cells for processes that produce energy there. It builds up if there isn't enough B12 in the blood to produce the necessary adenosylcobalamin - which is why it is used as a secondary marker of B12 deficiency.
"Methylmalonic acid is an organic acid of which the blood levels are usually raised in case of a B12 deficiency. Adenosylcobalamin – one of the two active forms of B12 – is a cofactor of the enzyme L-methylmalonyl-CoA- mutase, which converts L-methylmalonyl-Coa into succinyl-CoA. If adenosylcobalamin is lacking, excess D-methylmalonyl-CoA (precursor of L-methylmalonyl-CoA) is converted into methylmalonic acid(MMA) which causes raised blood levels of MMA. In short: a B12 deficiency (usually) causes high MMA."
B12 is transported on transcobalamin I and II. Transcobalamin II is the active transporter, for which most cells have receptors. The purpose of the portion of B12 carried on TC-I is not fully understood afaik.
I am no scientist: Grade 1 CSE in Environmental Science my closest qualification !
But something isn't making sense to me.
Can either of you explain why my MMA was found to be raised after having been started on the B12 injection regime for B12 deficiency, and despite frequent injections from that point (2 per week), it remained raised for three years ? Surely the six loading injections alone should have brought my MMA into normal range ?
Three years later, a sixth MMA test finally gave a level within range.
[My MMA was not tested before the B12 injections were started, so I cannot know what my level was then. I was tested because I continued to deteriorate after B12 injections started - which led my GP to suspect functional B12 deficiency. The MMA test result gave her the diagnosis confirmed by the testing laboratory - as she had already checked and rejected renal malfunction as cause. ]
Nothing else was found: Coeliac disease, bowel cancer, SIBO, etc. all ruled out along the way by consultants and tests, scans, biopsies.
No, I never understood this Cherylclaire. It keeps me awake at night 😅 I know you mentioned no genetic issues were found but there has to be an underlying biochemistry issue, either genetic or relating to a co-factor. It disappoints me greatly that your medical team did not continue to dig into the reasons for that.
Normally MMA drops very quickly after starting treatment as far I know.
.... there is also haptocorrin/ R-binder - which is secreted (another secret ?) firstly by salivary glands, unless like me, you have saliva duct strictures, in which case it is a bit hampered ....and I get a bit Hamstered ! The initial protective coating provided for B12 from food (extrinsic factor)is then compromised.
Have you read "Transcobalamin II 775G>C polymorphism and indices of vitamin B12 status in healthy older adults" (Joshua W Miller et al: Blood, 15 July 2002)?
It suggests that one genotype (of 3 found) might be more able than others to efficiently deliver B12 to tissue level, so TCII genotype could influence susceptibility to B12 deficiency. Mostly incomprehensible to me, but interesting.
Not a large sample group and only 20 of those were women, but still....
Gets quite hard to discuss B12 deficiency without mention of genetic research, doesn't it ? Especially where the cause is hereditary.
The first haptocorrin* needed in B12 process is located in saliva glands.
Exit route (saliva ducts) can end up, like paper drinking straws, squished in places and less useful, crooked instead of straight - saliva duct strictures ! This can block saliva (and haptocorrin) in glands, causing swelling when hungry, reading a menu, cooking etc. Sometimes a long wait for the Hamsterface to reduce down to normal !
The answer to this is a procedure where a tiny camera and balloon on a small tube make the backward journey through ducts, and where a stricture is found, the balloon is inflated to stretch it back out again. A delicate procedure that you can watch live on screen - and yes, as painful as it sounds.
As with anything else, this is not always a miracle cure.
*The very first haptocorrin comes from breast-milk.
Someone will correct me if I am wrong, but, if you have high serum B12 then Intrinsic Factor is very unlikely to be the cause, as it is IF, secreted in the stomach, that enables the B12 to be picked up and absorbed in the terminal ileum.
IF is used in the absorption of B12 in the gut and does nothing once this has happened - it doesn't help with transport or absorption into cells - that is done by transcobolamin - a completely different protein.
High levels of serum B12 can lead to false positive results of IFAB test - but that's usually levels that are well above the measurable scale.
Hydroxy is NOT a methylated form of B12.
High levels of serum B12 can affect cellular absorption in some people - causal mechanisms are not, as far as I am aware, understood. This seems to affect the efficiency of absorption rather than absorption itself and keeping levels very high with injections can actually result in enough B12 getting through - like overflowing a damn to make sure that water gets down below the damn.
Strictly speaking genetics is off topic for this forum.
If it helps SunriseDaily this was also me, or at least high normal B12 serum yet with neurological deficiency symptoms (elevated MMA too). I was on oral B12 supplements at the time so I blamed those, but I also was borderline deficient for folate and I have since found out my MTHFR would suggest I could have problems with processing folate, so 🤷♀️
I’ve concluded that there’s probably a double set of issues going on. I have a PA diagnosis (positive to parietal gastric cells and low stomach acid, plus my dad had symptoms consistent with undiagnosed PA), yet for whatever reason there’s also something screwy about my methylation process too. The latter definitely gets thrown every time I have COVID, leading to various persistent symptoms which slowly go away after a few months of trying to regulate it all again with treatment. There is a good research paper suggesting that COVID can throw methylation - I should be able to dig it out later.
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B12 deficiency with High Serum B12?
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Recent PA diagnosis, serum levels high from oral cyanocobalamin, symptoms persist
very high B12 no injections or supplements 
