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Pernicious Anaemia Society
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I recent had what I thought was going to be an Intrinsic Factor Antibody blood test, it actually transpires that my bloods were sent on for further tests (IF not done I don't believe) but I have now had a Serum Methylmalonic Acid Level test done which gives a result of 0.33 (range 0 - .29 umol/L). The IF test was originally requested due to suspected B12 deficiency but it seems I am now travelling down a rabbit hole.

The GP (who is new btw and seems to actually listen) spoke to me about my results and explained she did not want to put be straight onto B12 injections until she spoke to a specialist haematologist as my results are complicated. I also have a low Serum Total Protein 64 (range 66 - 87g/L) and generally my Folate is low but at present its had a boost by tablets and is 20 (range 4.6 - 18.7 ug/L) at present but it never stays up there.

Obviously having spent years trying to get someone to listen I am now relieved but also concerned, initially I though I might have perinous anaemia but my results are not leading in that direction.

Any clues anyone - all paths will be followed thanks



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Hi Geordi I'm not medically qualified nor do I understand all the technical jargon, but don't worry if you do have P.A. as I've had it for 45 years and I'm still "clivealive" at 75.

I hope your "new" doctor gets things sorted quickly so that you can get the treatment you need. I wish you well.


PA is one possible cause of a B12 deficiency but there are others. MMA is a test that can help clarify if there is an underlying B12 deficiency - the results will be high if there isn't enough B12 ... but there are other things that can also cause a high reading - {edited}

The symptoms of PA are the symptoms of the underlying B12 deficiency that it causes - and unless it can be demonstrated that it is down to your diet not having B12 in it the cause will be absorption in some shape or form - which would mean the same treatment.

Do you know if your blood test showed any signs of macrocytosis - larger and rounder blood cells than normal. Many medics think that this has to be present for there to be a B12 deficiency so will be confused if it isn't - though something like 30% of people develop symptoms due to the effects on other systems in the body well before any macrocytosis shows up in the bloods. So worth looking at what symptoms you have as part of the diagnosis and worth making sure that your GP is aware that macrocytosis isn't always present.

As folate and B12 are used by a lot of the body's systems together there is also a significant overlap in the symptoms of folate and B12 deficiency which may complicate things further.

If you have neurological symptoms then those need to be treated as a matter of urgency - but you do need to work with your GP - particularly given that there seems to be something going on with your protein levels - which could point to something else being involved that could affect the correct course of treatment.


I thought that it was homocysteine that could be elevated with both folate and B12 deficiency, whereas MMA was specific to B12 only?


thanks Jade - you are correct that folate doesn't affect MMA - my bad - however, there are other things that can cause high MMA


Great thanks :)


IIf GPs suspected b12 deficiency , I am surprised that IFA test has not been done.

See page 29 of the "BCSH Cobalamin and Folate Guidelines".

This gives the recommended process doctors should follow in the UK with someone they suspect has B12 deficiency, including when to order an IFA test. Some GPs may not be aware of this document therefore may not be following its recommendations.

Page 8 gives details of UK b12 treatment.

I gave a copy of whole document to my GPs along with a copy of Martyn Hooper's latest book "What You Need to Know About Pernicious Anaemia and Vitamin B12 Deficiency"

UK B12 websites





Another B12 book I found useful is "Could It Be B12" by Sally Pacholok and JJ. Stuart.


Thank you all, I think the IFA test was done but only marked as n/a so assume it was negative, I am still unsure why the bloods were sent on though. Also how do I tell if I have macrocytosis. I keep a note of all my bloods and have access to all result on patient access site after a struggle with surgery and various arguments about paying £10 per sheet of paper to get results.

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n/a often means not applicable so it could be that the IFA test was not done. GP surgery should be able to tell you what n/a means in your case.

If it was my test I'd want to know why they thought it was not applicable especially if I was symptomatic for B12 deficiency.

"Also how do I tell if I have macrocytosis."

Have you got copies of recent results for FBC (Full Blood Count)?

High MCV and high MCH on the FBC can indicate the possibility of macrocytosis (enlarged red blood cells). Macrocytosis is sometimes found in those who have low b12 and those with low folate. Be warned that macrocytosis can be masked/hidden in those who have low iron as well as low b12/low folate as low iron can lead to microcytosis(small red blood cells).




"initially I though I might have perinous anaemia but my results are not leading in that direction."

Even if IFA test comes back negative, it is still possible to have PA. Some people have Antibody Negative PA which means the IFA test will come back negative. Antibody Negative PA is mentioned on page 29 of the "BCSH Cobalamin and Folate Guidelines"

Martyn Hooper, the chair of the PAS, tested negative on the IFA test more than once before testing positive.

I hope your GP has read the BCSH Cobalamin and Folate Guidelines. I was sure my Gps hadn't which is why I gave them a copy of the whole document.

fbirder has compiled a useful summary of mainly UK b12 documents. There is a link to summary on his profile page and one in the third pinned post. i take a copy of it to appts where B12 might be discussed.

In teh UK, my understanding is that people who are symptomatic for B12 deficiency are supposed to be treated even if their b12 blood levels are normal range. See BCSH Cobalamin Guidelines for more info and also BMj article on b12


What symptoms do you have? Any neurological symptoms? See links to symptoms lists.




I am not a medic just a person who has struggled to get a diagnosis.

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"I keep a note of all my bloods and have access to all result on patient access"

I think that patient online access is only to a summary so there may be info in medcial records that is not available online.





Wanted to add that macrocytosis may show up on a blood film aka blood smear. This test may show macrocytic cells and microcytic cells in someone who has both low b12 and/or low folate plus low iron.


Have you got any blood relatives who have PA?



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Hi Geordie. Just wondering what your serum B12 level was?

Also, in case you don't know, both the anti-IF and PAC tests are only 50% accurate so just because the IF has come back negative, it does not necessarily mean that you do not have PA. in addition, it's also possible to have antibody negative PA.

Martyn Hooper, the chair of the PAS tested negative three times before he got a positive - and he clearly had PA all along.

And I agree with Gambit, if you have neurological symptoms, you need to be treated with B12 injections as a matter of urgency (to avoid potentially irreparable neurological damage).

There are some pinned posts to the right of the homepage which give very good information about PA and vitamin B12 deficiency. Might be worth a read. And some members print them off and take to show their GP's, who are often I'll informed about B12 deficiency / PA.

Your GP is right to want to look at other possibilities but should not lose sight of the need for B12 replacement if your B12 is low. Especially if you have neurological symptoms.

Anybody here who reads you post will know about the 'rabbit hole' scenario! It's so frustrating having to constantly push for answers, whilst trying to educate doctors (some who are well meaning, some who are not).

Good luck with your search for answers and please post any questions if you need help with climbing out of that rabbit hole,

Be good to hear how you get on x


My B12 was 277 (range 197-771 ng/L) but it has slowly been declining over time and serum folate is 20 (range 4.6-18.7 ug/L) but was 3.7 prior to supplements which I have been given previously but it only boosts the level initially. I also have large dose b12 tablets from the doc but my level continued to decrease (prior to supplement b12 was 294) clearly something not working properly, or should I say some else, oh deep joy 😓


Hi Geordie. Just a quick word about the B12 tablets. if you have an absorption problem then these just won't work, and this could explain why your B12 levels are still falling, although on high dose tablets!

It's seems fairly clear that what you need is B12 injections!

I'd say (maybe a little tongue in cheek) that the thing not working properly is your GP. 😄 But as you say she's listening, so that's a really good start. Many would love a GP who listens!

Good luck with it all and please let us know how it goes x

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Hi foggyme, don't sublinguals work even with an absorption problem b/c they are absorbed into the bloodstream via capillaries? Isn't it the tablets that you swallow and go through the stomach that don't work?

Just checking! :-)


Hi Ndodge. Grief Ndodge, you're right. On both counts. I typed in sublinguals when I should have typed in tablets (what Geordie's doctor had advised). So...a slip of the brain...

Thanks for pointing out...Have edited my post...I'd so hate to misguide anybody 😄.

It's a good job you have such an eagle eye!


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I knew it was a simple mistype! We all do it at one time or another. I know I have.

Your friend, eagle eye dodge. :)

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