Pernicious Anaemia Society
14,198 members10,170 posts

HELP Please High B12 result

Hi I am wondering if anyone can help me ?? I was having B12 injections I have been a coeliac for 24 years and had a small fibre neuropathy so GP agreed the injections .. Last year I became hypothyroid and been on Levothyroxine .. But in May last year my B12 bloods came back over 2000 so my GP said to stop them and see what happens ? On the 1st April this year I had bloods taken as my arms were so painful and weak so I thought I needed a increase in thyroid meds ? ..My results show my B12 is still over 2000 and I've had no injections and not supplemented .im worried as my full blood count also showed White cell count high ,Red cell count High Haematocrit high Neutrophil high and lymphocyte high ...I've started to worry about POLYEYTHEMIA Vera :( .. I am on health unlocked thyroid and someone left me a message to say ask you guys about high B12 as they seemed to think it would still stay high ? Thank you in advance xxxxxxxxxx

9 Replies

Hi Lynnwin.

I believe your B12 test result is no cause for concern.  Over on the old Pernicious Anaemia Society forum -- which no longer operates, but is still open for others' perusal and learning -- it was noted that some of us having severe permanent neuro complications were doing worse -- not even keeping stable -- without our levels being kept in excess of 2000.  Once there is deficiency established, testing reference ranges for "normal" may or may not be fair indications as to the adequacy of treatment.

Yes, the timing of your most recent injection(s) and and/or supplementation prior to your blood testing would have bearing on the levels in your blood.  If you were indeed deficient and had no injections nor supplementation for some eleven months between blood tests, and if 2000 were the cut-off detection limit, it could fairly be expected that your levels were declining over the period between those blood tests -- your levels would most likely have been higher at the time of your prior blood test.

Some of us (I gather it is a minority among us) have leukocytosis.  I have read of some (long-ago) historical cases in which Pernicious Anemia was first misdiagnosed as Leukemia, so I expect that those cases had this (leukocytosis) commonality.  This is not to alarm you, only to let you know that these two conditions have been known to be coincident in some persons.

As to high white cell counts (absolute numbers), you will find that your Doctors are at least as interested also in the differentials -- i.e., calculations of the relative proportions among the different type cells.  Reference to differentials as well can give them some good indications as to what is going on with your blood.

I urge you to have your Doctor send you to a Hematologist to figure out what is going on with your blood.  I understand your being worried, and I know it is difficult for you not to worry, but listen -- okay to be concerned, but let your Doctors have their job of being worried and bothered about it.  Remind yourself as often as you need to that worrying about it is their job, not yours! Whatever is the problem, you can have it thoroughly checked out and treated or managed if needed.


"last year my B12 bloods came back over 2000 so my GP said to stop them and see what happens ?"

Fbirder has a summary of useful quotes from mainly UK documents that may be helpful to read. If you pm him I'm sure he'll pass it on.

Have you contacted the PAS? Lifetime membership costs £20. They can point you to useful info. Have you ever been tested for PA?


01656 769 717

Have you got MCV and MCH results on your FBC?

Next link has info on writing to Gp if unhappy with treatment.


Hi sleepybunny thank you so much for your reply yes they did do mcv and mch and they were fine :) I have had high on the Red cell distribution width before but not this time and that was ages ago when my b12 was 458 ..and my RBC has been high before :( ..yes I think I was tested years ago when I had awful neuropathy ended up in a Harley street clinic seeing a endocrinologist as no one could help me after spending thousands trying to get well :( .. I had the intrinsic factor test and that was ok .. The endo told my GP to treat the symptoms not the blood results which he did by b12 injections ...When the neuropathy eased they stopped the injections and when it returned they did them again grrr I see now that this wrong :( 

Thank you for the info I will definitely be looking into it ..xxxxxxxxxxxxxxx 


High B12 should not be used as a reason stop your B12 - once supplementation has started results of serum test do not mean anything unless they continue to be low.

There is a condition called functional deficiency where you have high levels of B12 in serum but still show all the signs of a B12 deficiency. One probable explanation is that some people have an auto-immune response to high levels of B12 in itheir blood that creates a protein that binds to the B12 stopping it fro passing through to the cells where it is needed - there seems to have been quite a bit of research on it in the 1970s but since then seems to have been forgotten.  Treatment seems to be to keep serum levels really high - as the response above suggests so that there is more B12 there than the body can bind and enough gets through to the cells where it is needed. 

B12 deficiency is not a blood disorder - blood disorders can be a symptom of a B12 deficiency but they aren't always the first with a significant number of people having very advanced neurological symptoms long before they develop any form of anaemia.

I can't function unless my B12 levels are astronomic -  tend to keep them that way by using nasal sprays and some subliguals and have to start supplementing within 24 hours of a maintenance shot.  I do self inject ocassionally as well.

Personally I suspect that it is the high serum spike caused by the injections that triggers the reaction.   My mother and I seem to need ridiculous amounts of b12.  My aunt and brother - who have never been formally diagnosed - but have symtpom - use nasal sprays and require much lower doses.  Only provlem is - particularly given that the B12 is being bound so it stays in the blood - is that I'd have to wait avery long time being functionally deficient if I wanted to get it all out of my system - not sure I'd be alive at the end of the wait.

Just for the record - susceptibility to stress and high levels of anxiety are one of the key neuropsychiatric symptoms of B12D.


Here's my summary what Sleepybunny referred to -


" I had the intrinsic factor test and that was ok "

"yes they did do mcv and mch and they were fine"

I hope whoever tested you is aware that it is possible to have PA even if the IFA test is negative. The "BCSH Cobalamin and Folate guidelines" refer to Antibody Negative PA on page 29 and elsewhere in the document. Martyn Hooper, the chair of the PAS tested negative more than once before testing positive.

Did you see copies of your MCV and MCH results? I learnt from bitter experience that what I was told was "normal" or "fine" over the phone or even to my face was not always "normal" when I saw the copies. I get copies of all my blood tests. Most surgeries will charge per copy.


Hi thank you again for your reply :) yes I have the copies of my bloods and MCV OK and MCH OK :) .. Thinking the worse now with such a high B12 and no injection or supplements for a year :( .. Keep blaming everything on my hypothyroidism :( .. I have been deficient in B1 B2 B6 which I have been supplementing found out through private blood tests with Biolab but they have NO B12 in them :( ....think being a coeliac makes me deficient in them ? I've just ordered them again ..thank you for your time I really appreciate it 



I don't have much to offer regarding your concern. It sounds like your results are mainly high white cell counts. Maybe you're already familiar with this info, but Ed Uthman's book 'Understanding Anemia' has great descriptions of how the white blood cells work (He also has a webpage with more of his writing on various medical subjects ):

"White cells, or leukocytes, are the individual instruments in the great symphony that is the immune response. There are three major types of leukocytes involved in the inflammatory response, all of which not only circulate in the blood, but also reside and work in the solid tissues throughout the body. These major categories of white cells are neutrophils, monocytes, and lymphocytes.

Neutrophils, the most numerous of the circulating white cells, are considered the shock troops of the inflammatory response. When a microbial invader enters a normally sterile area of the body, millions of neutrophils accumulate at the site and attempt to destroy the invader by engulfing it and exposing it to an armamentarium of highly toxic substances. In the process of doing this, the neutrophils also fall victim to their own weapons. The innumerable dead neutrophils pile up and break down, to the point where their mass grave becomes visible to the naked eye as a creamy yellow material, called pus. One of the deadly chemicals produced by theses turned-on neutrophils before they die is an iron-containing substance called lactoferrin. When the inflammatory response is activated, neutrophils respond by markedly increasing their synthesis of lactoferrin and secreting it into the plasma (more on this later).

Monocytes, the least numerous of the three main leukocyte types, circulate around in the blood until they are needed at the battlefield to combat an unfriendly microbe. When they leave the circulation and enter the tissues, they transform into macrophages. (Remember from chapter 5 that macrophages are also a part of the reticuloendothelial system, charged with getting rid of aged red cells and readily scarfing up red cells coated with antibodies.) Macrophages are equally enthusiastic about engulfing and destroying infections agents, especially those that are coated with antibodies. Another function of macrophages is to take some of these engulfed organisms and “present” them to the cells that actually make the antibodies. You can think of the macrophage as the big goon who picks up the trouble-making punk by the collar, drags him before the local kingpin, Mr. Lymphocyte (see below), and then beats up his hapless victim at the behest of the boss.

Another function of macrophages in the marrow is to store iron and transfer it to developing red cell precursors for hemoglobin production. For the marrow macrophages to get their iron in the first place, they have to receive it from transferrin, the major iron transport protein in the blood. In conditions where the immune response is turned on, much of the lactoferrin produced by the neutrophils ends up going into the macrophages. Presumably this lactoferrin will be put to good use by the macrophages out on the battlefield, because lactoferrin is quite capable of killing bacteria. Back home in the marrow, however, the lactoferrin competes with transferrin for receptor sites on the macrophages. The iron in lactoferrin is not available for transfer to the developing red cells, so these go hungry, while more and more iron is piling up unused in the macrophages."

"Lymphocytes are the second most numerous of the three major types of white cells. They not only circulate in the blood but also reside in large numbers in so-called “lymphoid tissues” throughout the body. The classic example of lymphoid tissue is the lymph nodes, which are solid packages of lymphocytes. Other prominent areas of lymphoid tissue are found in the upper throat and digestive tract.

If the neutrophils and monocytes are the brawny enforcers in the war on microbes, then the lymphocytes are the brains. These little cells cannot engulf bacteria and other germs directly, but they can perform two other functions that are just as deadly. First, one class of lymphocytes, called B cells, can produce antibodies specific to the molecules sticking out on the surface of the invader. When functioning properly, these antibodies stick only onto those specific molecules that signify an enemy. Macrophages and neutrophils respond to the antibody tag by eating whatever the tag is attached to and leaving untagged cells alone. This is why the immune response can kill outsiders while leaving our own tissues untouched. The second deadly weapon at the lymphocyte’s command is the lymphokines, a motley assemblage of substances secreted by lymphocytes involved in the inflammatory/immune response. Lymphokines act as intermediaries among lymphocytes, variously hiking up and toning down inflammatory activity so as to meet infectious threats with measured response and minimal collateral damage. Several of these lymphokines have the property of being able to inhibit cell growth. The influence of these cells on erythroblasts is to make them less responsive to erythropoietin stimulation. The effects of this growth-inhibiting property of lymphokines are not limited to RBC precursors; other cells are similarly affected. For instance, during periods of acute or chronic inflammation, nails and hair also grow more slowly."


Thank you so much for your detailed response so kind of you to take the time to type all that :) it's very interesting :) goi,g to have a look at the link also .. Thank you so much xxxxx


You may also like...