Pernicious Anaemia Society

can you have a normal vit b 12 reading when the intrinsic factor is compromised?

worried sick about my sister, 7 weeks off work now due to 'severe anaemia', iron tablets have improved the FBC reading, symptoms are complicated occurring every second day, lethargic, low energy, dizzy, palpitations, sore joints, waking from sleep with heart racing and head spinning, and change of pallor to greyish colour, several tests have been done, large bowel, stomach, heart, lungs and brain have been examined and thankfully all appears ok, accept from some cells that are showing a predisposition to 'coelic disease' but today that was ruled out as cause for symptoms. all research on our behalf have lead back to 'vitamin b 12 deficiency' yet the doctor says her reading for this level in her blood is normal ? No check has been made for the compromise of the 'intrinsic factor' but how do you suggest that this is what you feel greatly may be the problem, no one will listen to a concerned sister, or indeed where she got her information, that they would find strange! I would be grateful for any information or help thank you in advance.

15 Replies

You can most certainly have a normal serum B12 and be suffering from B12 deficiency. You need look no further than the new British Committee for Standards in Haematology (BCSH) guidelines, which you can copy and take to the doctor:

"patients with strong clinical features of cobalamin deficiency may have serum cobalamin levels which lie within the reference range (false normal cobalamin level)."

Has she had tests for thyroid, cortisol, folate, ferritin, vit D, calcium? What was her actual serum B12 result? She needs to get copies of all her test results because a doctor's idea of "normal" doesn't often bear any correlation to what the test results are actually telling you. And a severe iron deficiency would mask any signs of macrocytosis in the FBC.

Personally, I would also want clarification on the Coeliac test. Why was it ruled out? I would be giving up gluten pronto if I'd been told I had a "predisposition" to Coeliac disease. In fact, I did give it up with a negative test result, I think it's that important as a potential driver of autoimmune disease.

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Hi Hampster1

Please could I seek your help with a problem I have not personally come across before, at present it is just a theory, but one, the potential of which interests me greatly and I think it may also interest you too. I have a 30 year old Grandson, who's B12 we tested a few months ago due to problems. His B12 was in the grey area and we ran an MMA which came back as B12 = 25pmol/L. Ref. 25 - 70. B12 therefore deficient. The MMA resulted in a reading of 169 Ref. 0 - 280. resulting in B12 satisfactory at that time. Obviously we will re-test in due course. However; I give you these readings simply as background. He was advised not to medicate pending further tests in a month or two.

His main problem at the moment is his face and neck, he suffers from deep reddening of the tissues and large abscess like protrusions rise on the skin, eventually these will burst and puss will discharge. His doctors and a Dermatologist have made a diagnosis, sadly all their efforts, with creams, antibiotics and UV treatments, have simply resulted in a worsening of the condition, until, now he is in continual pain, often cannot go to work and has no social life whatsoever. He is self-employed and so his income is also suffering badly. In view of this, I feel perhaps his Cortisol level should also have been checked by his GP ??

Now I am wondering if there could be an internal problem here and all of this is not coming from an external infection, allergic reaction, etc., but could this be an as yet, perhaps undiscovered side effect of a B12 problem, perhaps something in his metabolism, which may be linked to a low B12. He has also recently started to develop Neuro symptoms, I found this out only last night when he rang me. On questioning him, he scored 6 out of 8 points on my chart for Neuro. symptoms, so that obviously needs addressing asap. My question is, have you read any research that indicates such problems could be inter-connected ?

I also feel that a new full range of bloods is called for, but as we live 120 miles apart, it's not easy for me to get involved, although I am arranging for him to be seen by a Prof. in this type of problem. I'm also wondering if my theory could put us on the edge of something totally new. What do you think ? I would have sent you all this in a personal message, but I couldn't find how that works on this site.

Hope to be favoured with your thoughts on this, even if you think I'm barking up the wrong tree.

Best wishes B12Tx


Firstly, I think he should have been treated based on the active B12 result. None of these tests are a gold standard, you can test normal for all of them and still have a problem with B12. Out of interest did he have his folate and homocysteine checked? I think skin problems can be associated with elevated homocysteine, this is from the website:

"Without B12 a person builds up homocysteine which makes them depressed and irritable (yes, I know a few of those!). It also creates skin problems such as acne, eczma, rashes, which is the body trying to get rid of the extra homocysteine. We had a case where someone developed pimples (fatty nodules) all over his arms, back and chest which were the fat trying to form encasements around the homocysteine to stop it poisoning the body."

My other thought is could it be Rosacea? This is also associated with B12d.

Just a little anecdote. My husband suffers from Rosacea, and after my diagnosis I urged him to get his B12 checked (he is otherwise completely healthy). To our surprise his B12 came back below 200, but above the bottom of the reference range. I sent him off to St Thomas' for active B12, MMA and homocysteine. He was considered "fine" although his results were quite borderline in my mind. His homocysteine in particular was around 16, with top of the range 15. The range is actually set too high from what I have read about it, it is better to be down around 7. So to me he needed B12 and folate and a B-complex, in the most active forms, because this was potentially pointing to a sluggish methylation issue. And since he was not otherwise symptomatic we opted for sublinguals. If there's any sign of neuro symptoms I'll get him on jabs.

The point of this is I'm thinking since you yourself believe methylB12 might be better for you and active folate, there could be a familial methylation cycle defect at play?

If you haven't already seen this, it's a really good article about homocysteine:

However I think if he now has neuro symptoms he really needs jabs as soon as possible.

A couple of studies re normal test results but response to B12 therapy:

"It is concluded that Cbl, MMA, and HCys levels fluctuate with time and neither predict nor preclude the presence of Cbl-responsive hematologic or neurologic disorders."

"Serum B(12), homocysteine and methylmalonic acid levels are unreliable predictors of B(12)-responsive neurologic disorders, and should be thoroughly investigated and presumptively treated in patients with unexplained leukoencephalopathy because even long-standing deficits may be reversible."

H x


Hi Hampster

Many thanks for your thoughts, re Rosacea, I trust you are referring to Acne Rosacea, My medical knowledge of dermatology is very limited, but I would have thought that the pictures he has sent me, would perhaps fit better with Acne Vulgaris.

I will check out the links you have so kindly highlighted and revert to you afterward of course. My main reason for my question, was had you experience, or indeed had knowledge of any direct connection between skin probs. and B12, which it appears you have. If you can send me your E-mail address by private message, I will be happy to send you a number of photographs Stephen has sent to me, plus my details. I would of course then value your opinion. Now at 71 and after 52 years of very happy marriage and 10 years of retirement, my brains not absorbing new technology as fast as you young guys. I get there, it just takes a little longer.

Many thanks for your time and interest, B12Tx


I probably sounded like I know more than I do! That's the extent of it I'm afraid.


Ok no probs., I guess that makes two of us, every day there are new problems and all too few answers I'm afraid, as a very wise man said to me a few weeks back. You might be interested in this glimmer of possibility.

Many thanks for all your efforts


thank you so much, they have put her through the mill, she has had so many tests, they have sent her last set of bloods to England we can't test them here apparently they are testing for auto immune diseases lupus, rheumatoid arthritis, and a blanket testing for other things, she was tested for thyroid that is normal, it was the initial blood results that sent the clinic into panic mode, as her ferritin was on the floor, they phoned deeply concerned and asked her to get to a chemist asap and to get iron tablets and start taking them she was on 3 a day for weeks reduced now to 2 a day, and this is the puzzle her bloods are showing brilliant now, all up and back to normal, but she is not, and I worry about this change of colour, I feel it is lack of oxygen as a result of the red cells being clumped together and not having free movement, the top doc in the assessment unit said no to Coelic disease, that she felt it was 'post infection syndrom' we are nearly demented, and also now we have something else going on, which they feel is a separate issue, and will be dealt with in gyny. she had a letter from her doctor with all the info on it but it was kept by the assessment unit, I will ask can she remember the count for vitamin b 12, I have a reliable source, but not one 'science' would except and dear lord I know she needs the INTRINSIC FACTOR checked, she is pushing herself to be normal and she is so tired, I will print off a copy of the above report, maybe send it to her gp on the quiet.I am grateful to have someone to talk to, thank you



I am sorry to hear that your Sister and you are experiencing the symptoms explained above.

I am not a medical expert only a sufferer of PA and a volunteer for the Society.

However I can help with the basics once you have answered a few questions.

You say her B12 levels have been checked? When was this and what was the level, you need to find this out just by a call or asking for a print off of blood records. Don't just let them say the level was ok you need a figure and the measurement it was measured in.

If it was not done recently and she has not been supplementing with B12 in anyway then she will need to get another b12 level test but ask to have the test for PA at the same time to save having to go for too many blood tests. (if you suggest you found out someone in the family had PA they are more likely to test for it)

What you have to realise is that the test to check B12 levels and for PA are really not that accurate so you have to be aware of what to do and what else to check.

There is a study to show that if your B12 levels are under 500 your brain is shrinking twice as fast than someone whose levels are over 500, with just this in mind my personal thoughts are that if a person is under 500 they should have some form of supplementation of B12 to make sure they stay above this level t protect the brain as well as anything else that could be going on behind the scenes!

You cannot overdose on B12 it is a water soluble vitamin, so if anything if you have too much you will only waste it by it coming our in your water.

I will leave it there for now and let me know how you get on and I will give you more help.

Also our new website will be up and running from the second week in June and hopefully it will be easier to navigate and find all the answers you need.

Best wishes


again thank you for this advice, you see my concern is this, if the 'intrinsic factor' is compromised then so is absorption of the vitamin, but this is a special test and they 'don't normally' do it, when they see that you have sufficient B12 in your blood, I am going to ask her what the reading was, they sent her with a report to an assessment centre where every organ was scanned or xrayed and they said she was a 'medical mystery' for god sake why won't they test for this, and in truth she is now at this point of saying look they have done A B and C and found nothing so I am going just get on with it, but truth to tell she is not fit too, she has energy in the morning and then falls down in evening needs to go to bed etc all of this so foreign to her, and why this tiredness takes over, her colour changes to a greyish colour, she now feels she has annoyed enough of them, and will probally won't say anymore until the bloods they sent to England come back, they are been checked for lupus, rheumatoid arthritis etc so that takes 4 to 6 weeks, maybe they will give an answer. thank you for your help


please don't be annoyed with me I have asked my sister to get a copy of her bloods and she is going too, and of course anyway she informs me all is NORMAL but she is so busy going to every and any consultant that ever existed! The update is this, all auto immune diseases tested by the latest consultant a dermatologists and a biopsy of her skin rash [this is new] are normal and have been ruled out no later than today! There is also a new symptom with the tiredness, whoozy head, palpitations, and utter exhaustion etc and that is 'spasms' we are over a year down the road now, she has also been prescribed anti anxiety medication, as it is almost accepted now she has 'post viral syndrom' she is going to celebrate her 50th birthday tomorrow, and I would love to take her to someone who can fill in the pieces of this jigsaw and give her back her health! She is out of work now for almost all of that time, it is so hard to see her this way. Something caused her iron levels to drop to a very dangerous low, but of course it is a 'VIRUS' which is another term for 'don't know' somewhere here someone mentioned a hospital in London where she can have a complete check on her Vitamin B12 etc could you please mention that place again! Many thanks and sorry if I have annoyed anyone.


Hi Kiltyclogher

Just to give you a little more confidence to approach your doctor, may I just add, that I totally agree with everything Hampster has said to you, it is all very sound advice and your GP should be made to listen to it, the BCSH guidelines should convince him /her. All I would add, is that if this GP is going be be your sisters first line of treatment and of course medication, then perhaps it might be a good idea to purchase from Amazon, 2 books called "Could it be B12" one to read for yourselves and one to take and give to your GP as a present. Be diplomatic and it should be very well received. One last thing, PLEASE DO NOT ALLOW ANYONE TO BEGIN MEDICATING YOUR SISTER UNTIL YOU HAVE FULL AND COMPREHENSIVE DIAGNOSIS !!! Should the GP decide to try injecting your sister prior to all the tests Hampster has outlined, then the B12 may simply screw up all the test results, so please don't do it.

Good luck, hope your sister soon feels better B12T


she has been to her gp several times and not been before this for 4 years, as stated above they have every organ scanned etc and also her bloods are according to them good and that is suppose to reassure, only treatment recommended to date a 'good tonic' pharmaton ??? bloods have been sent to England and they will take 4 to 6 weeks for results after 9 weeks [I was corrected] it now is another couple of months, the gp won't be injecting anything as they don't believe there is a problem, they have not a clue why her bloods dropped so dramatically, and they believe 'virus or infection' but don't know what or which one it may be, all I know is she is very unwell and I hope soon they find out what is causing her to feel this way. thank you so much


I return to this site again, more than ever convinced that my sister has issues with her vitamin b 12 and the intrinsic factor, I have already indicated the serious amount of tests done, that have indicated that all organs are ok, and bloods sent to Germany [i think] for testing have returned with a negative for lupus, rheumatoid arthritis, and one other, her appointment with the consultant was to say the least iffy, 'we may never be able to name the virus' she said. Coelic which had been mentioned initially by registrar and dismissed was mentioned in passing again, more bloods have been taken and sent off, for what we don't know!!! The periods of wellness are greater now than the periods of unwellness and she returned to work, frustrated with no diagnoses and because work needed her, yet she still gets periods of exhaustion and woozy head and must lie down when she does, but lying down does not seem to take the woozy head away, she did approach the subject re vitamin b 12 with her GP who said well they don't normally check for intrinsic factor if reading is normal, end of story, would I be stepping over the line, if I went and seen GP and voiced my concerns??? Because that is what I am really feeling like doing, thank you for your time.


Perhaps the best thing for you to do is try to get your sister to get copies of all her blood tests, so she/you can see what has or not been tested, and what her serum B12 levels were when they were tested.

You may know the serum B12 test is not a gold standard and if your sister is willing perhaps get her to ask her GP to write a letter asking for her to have the active B12 test, and offer to pay for it, its about £18,- if you are in the UK, and can find your way to SThomas hospital in London.

For more info on the active B12 test see:

To exclude coalic a gastro would be best to see and have biopsies taken as blood test are not always 100% conclusive, but best to wait and see what results may come from the latest blood tests done.

I hope this helps,

Kind regards,



I am a retired nurse practitioner and have been having Hydroxocobalamin for 20 years and understand fully the awful symptoms you all suffer with! If you are in UK you can insist on a blood test with your GP for intrinsic factor!


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