Pernicious Anaemia Society
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Average diagnosis time

Does anyone know figures for the average time from first presenting with symptoms and getting a definitive diagnosis? I first noticed symptoms November 2014 and went to gp March 15. Eventually in April had b12 checked and levels low. In October I was put on 50 mcg tablets long term (had previously had some relief from symptoms with the tablets in July). However I just feel worse and worse every day (writing this is a struggle). Went to doctors today and they are redoing bloods and I mentioned a possibility of a false positive of the b12 due to taking the tablets. Dr said if levels high that shows I have enough b12! Only good thing is they are now checking anti intrinsic factor (which I requested last March but was told it was not reliable so no point! ) also checking for celiac (which I'm pretty confident I'm not). I just wondered how long on average others waited for a definitive diagnosis and then treatment. I am so exhausted and don't want to have to take time off work but am struggling daily. Thanks in advance

13 Replies

Pernicious Anemia is a immune condition.

Testing positive to antibodies for either Intrinsic Factor or Gastric Parietal Cells (or both) is a definitive test for the condition.

In my case the GP rang the pathology clinic when I had a low B12 result and asked if they could check for the antibodies.

A few days later he rang to tell me I was positive for IF antibodies but negative for GPC antibodies , but that that was a definitive diagnosis for PA.

Make sure your next blood tests include testing for Intrinsic Factor antibodies and Gastric Parietal Cell antibodies.

Good Luck


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High homocysteine can be an indicator of low B12. There's also a test for Methylmalonic Acid: "Some health professionals are convinced that MMA and homocysteine (which may be elevated when either B12 or folate are deficient) are valuable in detecting early and mild cases of B12 deficiency." Info from and there's a test for Active B12 via St Thomas's hospital, London.

It's difficult or impossible to get a definitive diagnosis for many who fall into the 'grey area' where they have all the symptoms but the tests say 'normal'.

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It took 4 years to get my diagnosis despite regular visits to gp. I now have SACD because of it. And I'm sure there are many people out there with the same problem.


The amounts of B12 you are being prescribed are very small and not going to help much if you have an absorption problem - they amount to 20x RDA and you would need to be taking at least 100 - probably nearer 1000-5000 RDA orally if you have an absorption problem.

The B12 serum test isn't a good test - it looks at all forms of B12 in blood so tells you nothing about what levels of active B12 used at cell level you have, and it also tells you nothing about what is going on at the cell level which is where the problems of B12 deficiency occur - B12D isn't a blood disorder though it does lead to blood disorders.

You may find this alert from UKNEQAS - the assay body that reviews quality assurance in the UK - useful in trying to alert your GP that serum B12 isn't a test that can be interpreted purely on the basis of results that come back - they need to look at the clinical situation

Sorry but I really think your GP is mistreating you and you should be on B12 shots not on the oral doses of B12 that are only useful if the cause of the deficiency is lack of B12 in your diet.

In answer to your question about length of time to diagnosis - 2 years certainly isn't uncommon but that is actually the time from going to doctor.

Looking back I'd have to say that I had an on-going deficiency for more than 40 years and probably had 5 years with symptoms getting really bad before it was picked up accidentally.

Over the weekend I was speaking to someone whose husband was hospitalised on boxing day with psychotic problems ... B12 was identified as a problem in the hospital but talking to her we could trace development of significant symptoms going back at least 5 years.

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Thanks everyone for all the information and useful links. It's really difficult as I'm sure you are all aware fighting your corner when so drained. I will wait for the intrinsic factor results and other tests to come back then go back armed with all this information. It definitely isn't dietary as I eat meat daily, I seem to crave it at times! Thanks again x

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It took Martyn Hooper, Chairman of the PAS two years to get a diagnosis of PA and, apparently, this is not uncommon.

I'm so sorry you are having this problem shuvs, as you are obviously aware that the Cyanocobalamin tablets GPs normally provide are not adequate and the correct treatment (injections for neurological symptoms) should be provided early on to prevent further damage.

Your GP has shown an incomplete understanding of B12 deficiency in referring only to blood levels in the serum B12 test and it might be a good idea to write or email the surgery with the latest BMJ research document below. There are templates for writing on this site under 'writing to your doctor' :

Re. blood levels, this is an extract from the latest BMJ research document - link below. It tells GP (bottom of page 4 under, "How is response to treatment assessed") :

"Cobalamin and transcobalamin levels are not helpful because they increase with vitamin B12 influx regardless of the effectiveness of treatment and retesting is not usually required".

In other words, once b12 treatment is started, the levels in the serum B12 test result will be high from supplementation but do not reflect whether B12 is being absorbed into the tissues. The clinical condition of the patient is what really matters......

The research document is supported by many research papers and is peer reviewed.

I hope you get the correct treatment soon.


I have been ill for over 10 years, highly symptomatic and still waiting for a diagnosis.

MMA, homocysteine and Active B12 tests can be helpful in establishing whether or not a patient has a b12 deficiency. The results of these tests may be affected if you are already taking B12.

I gave my GP a copy of the "BCSH Cobalamin and Folate guidelines". I was told the NHS should be following this document but some GPs are not aware of it.

Useful websites


01656 769467

If you leave a message they will get back to you within a few days.

Most local NHS have their own local management guidelines for B12 deficiency. Some of these local guidelines have not been updated since the BCSH Guidelines were published in 2014.

I've written some detailed posts over last few months which may have some useful info.

I am not a medic just a patient who wants people to have the info they need.

I found Martyn Hooper's latest book "What You Should Know About Pernicious Anaemia and Vitamin B12 Deficiency" helpful to read and also "Could It Be B12" by Sally Pacholok and JJ, Stuart


Just remembered that sometimes people who test negative for Coeliac disease can still have it.

Thyroid problems can sometimes occur together with b12 deficiency. Marz knows a lot about thyroid problems and the Thyroid UK forum is very active on HU.

"Only good thing is they are now checking anti intrinsic factor"

I was told by a haematologist that it was not worth testing IFA in someone with high levels of B12 from supplementation as the results would not be reliable.


Length of time to diagnosis depends on the reason why you have low B12. If it is due to pernicious anaemia (i.e. autoimmune), the IF and parietal cells antibodies blood tests will answer that question quite quickly. Same with coeliac disease. If it isn't those, and you aren't vegan, alcoholic or taking a medication that lowers B12, then other tests will (possibly) be done.

In my case: I was ill for 3+ years and then in 2011 my GP tested my B12 levels and I was deficient. I had lots of tests which showed that I don't have pernicious anaemia, I don't have coeliac disease; a colonoscopy and endoscopy ruled out any inflammation in my stomach or intestines that could account for malabsorption (such as Crohn's, colitis, gastritis etc.). (I don't come from a family that has any autoimmune diseases, so it's unlikely that I had false readings from blood tests.) However from the way my levels drop during the three months after each B12 injection, it is clear (according to my GP) that I am not absorbing B12 from food. A sehcat scan showed that I also don't absorb bile salts very well (they should be absorbed in the terminal ileum, along with B12), so the working hypothesis is that 'perhaps' I have fast transit (i.e. nothing stays there long enough to be absorbed). So at this point, nearly four years later, we still have no concrete idea as to why I don't absorb B12.

At this point for me the bottom line is - I don't absorb B12 but the injections work. I'm not sure I'll get a definitive answer.


I'm 43 and can't really remember a time without some symptoms.

I was bed ridden for about 2 years with all the symptoms about 20 years ago following acute liver degeneration and then a heart op. I was told I had CFS without having a test for B12. I took multivitamin tablets and eventually improved enough to work a bit.

My symptoms started increasing about 4 years ago and I started having blood tests again. My dentist referred me to a hospital in March 2014.

A locum pharmacist in my local chemist suggested that I asked to be tested for B12 which the hospital did. I had 4 tests below the range before I finally managed to get them to try loading doses in April 2015.

Many of my symptoms cleared and then returned. Eventually I managed to get daily jabs and was improving. I was referred to a neurologist who wrote to say "no change in treatment" and then my local surgery suddenly stopped them without telling me!

I now buy my own supplies and self inject. I continue to improve.

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Thanks again for all the responses. I struggled for years in my teens and early twenties for a diagnosis of endometriosis and don't relish the thought of another battle. However believe it or not your replies have given me some reassurance. From previous experience with endo knowing others have been there and understand is a support in itself. Great forum and delighted I found it.


Hi , found this link to an old HU post which i thought you might find interesting.

MTHFR gene mutation tests are available privately.


I started getting symptoms when I was expecting my youngest, who is now 25! Over the years I was told that I was stressed, depressed, anxious, etc, etc. Had a bought of severe anemia 10 years ago, which showed both macrolytic and iron deficiency anemia at the same time. Still no testing done. It was only when I was chatting to my parents (who both have P.A.) that the penny dropped. Doc still insisted that I was fine as serum B12 was 250, even though I told him I'd been taking supplements for decades. Performed a sit in in his office until he agreed to test I.F and Parietal cells. He told me that it was a waste of time and money, but did it to get rid of me. Two weeks later..............erm, you have P.A.! Really? I would never have guessed. Started on treatment just under a year ago. So it only took 24 years to get a diagnosis.


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