Pernicious Anaemia Society
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Consultant insists my B12 deficiency is down to diet

I am new to this forum and to the Pernicious Anaemia Society. I joined following a recent diagnosis of B12 deficiency. I have just completed a two week programme of b12 injections - 6 in all.

Pernicious Anaemia runs in my family. My father had it and so did his mother. I also have other autoimmune conditions, including hypothyroidism. I also have iron deficiency anaemia and, pre-menopause, I had endometriosis. I have also been told that I may have fibromyalgia, because of longstanding symptoms of joint pain, fatigue and terrible brain fog that has really affected my productivity at work. I have also recently been diagnosed with diverticular disease.

During the past year I have had two episodes of post menopausal bleeding, which started me on a long journey to discover what has caused it. I have been tested for ovarian, stomach, colon and womb cancer and, thankfully, I have none of them. Along the way I had many blood tests, one of which showed that I have iron deficiency anaemia. I last had this about 10 years ago when I had heavy periods. My ferritin level is currently around 10 but my doctor doesn't think that two short episodes of bleeding would have caused this drop in iron. I tend to agree with her. A few weeks ago, I suggested to my GP that I have my B12 levels tested because of the family link. She was sceptical but agreed. The level came back as 169. I wasn't surprised by this and was pleased that at least I could be treated for it and that the injections might even make me feel better.

Since then I have seen a gastroenterologist for a colonoscopy and endoscopy and he is now concluding that my iron and B12deficiencies are caused by diet. He has written to my doctor to say that he may refer me to a dietitian.

I am deeply disappointed by his diagnosis because I really feel that it is wrong. I eat meat, including red meat and I love fish. I eat eggs and dairy, including natural yoghurt and a fair bit of milk every day. These are all good sources of vitamin B12. I also eat lots of green vegetables and other iron rich foods. On top of this, I have a very similar autoimmune profile to my father and pernicious anaemia runs in my family so I don't understand why the consultant is discounting it.

I am now very concerned that following my loading doses of B12, I won't receive any more injections and that, once again, I will need to embark on a battle to get properly diagnosed and treated.

Any advice that society members could give me on how to tackle this would be very welcome.

Many thanks.

31 Replies

Wow! Nattilydressed, there are others on this forum who will come to your assistance with their better and more qualified advice but my first and immediate thought on reading your post is that no matter how high in B12 your diet may be if you have an absorption problem it may not be getting to where it needs to be - hence the symptoms - which your doctor needs to address and treat.

I hope you continue to get your injections as you need and wish you well for the future.


Thank you clivealive. Yes, I feel that the gastroenterologist is jumping immediately to the conclusion that my B12 deficiency is diet related when the signs are that it could be absorption-related.

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As you are Hypo - you may be suffering from LOW stomach acid. This will prevent the breaking down of proteins in the stomach - so B12 and other nutrients can be released.

Are you being optimally treated for your thyroid ? Iron - Ferritin - Folate - B12 - VitD are all very often low in their respective ranges due to the lowered metabolism and other issues. Your Ferritin needs to be around mid-range. Are you being treated ?

Do you know your FT3 levels ? After the brain the gut has the most receptors for T3 so when low things can go wrong. Perhaps you have Hashimotos ? - have you been tested ? Although you did refer to your thyroid along with other auto-immune issues.

Fibromyalgia can also be linked to low T3. If you have any thyroid test results with ranges then post them here or on TUK and people will comment. Happy to help.

I was diagnosed with Fibro in 2000 - Hashimotos in 2005 and have been having weekly B12 injections for almost two years due gut surgery that involved the Terminal Ileum. Crohns diagnosed over 40 years ago - but doing fine ! Easier for me as I live in Crete.

If you have symptoms of B12 deficiency then perhaps it would help to discuss the Guidelines with your GP.

Check out other posts here - eg sleepybunny - Polaris - Gambit - they always have a wealth of knowledge to share.

Once you have Fibro and IBS on your notes - it will be difficult to get past that to find the root cause. Endometriosis can also be linked to low thyroid as can so many things.

Do hope you soon receive the treatment you deserve :-)


Many thanks Marz. These guidelines are useful and I will discuss them with my GP when I see her next week.

In response to your questions:

- I am taking ferrous Fumarate for the low ferritin - have only just started on them.

- I haven't been tested for Hashimoto's.

- I don't know if I am being treated optimally for hypothyroidism. I have a test once a year and for many years they have told me that the results are within the normal range, although I have not seen the results myself. Will def ask to do so now. I was diagnosed with hypo in my late 20s and a couple of GPs have since remarked that this is quite young to have it.

- I'm afraid I don't know what FT3 is.

Glad to hear that you are doing OK, although it sounds like you have had lots to put up with. Hope you continue to get the treatment you need.


FT3 is Free T3. When you take your Levo/T4 pills they have to convert into the active thyroid hormone T3. T4 is a storage hormone and needs good levels of Ferritin/Iron/Folate to aid in the conversion. It seems GP's/Labs overlook this important test due to costs. However without this result it is impossible to know what is going on with the Thyroid.

You can have private testing done through Thyroid UK with a discount.

There is a package that also includes the anti-bodies and vitamins and minerals I believe. Well worth doing to know where you are if your Doc is not co-operative.

Saying you are within the normal range is not good enough. You can ask for copies of your test results as your legal right so you can monitor your own progress. Where you are in the range is important. TSH needs to be 1 or under as you are on treatment - and the FT4 and FT3 needs to be in the upper quartile of the range. Docs rely too heavily on the ranges and the basic TSH test. Normal is an opinion and not a result. Anti-TPO and Anti-Tg are the anti-bodies that also need to be tested to confirm Hashimotos or Auto-immune Thyroiditis. How you feel is so important and all these other conditions ? - well they can all be linked to the Thyroid.

On the above Thyroid UK link you will find the link to the information about obtaining your results and the Data Protection Act.

I found that having the VitD tested and treated was also helpful in my recovery. In spite of living in the sun since 2004 my levels were low. You can click onto my name to read my edited profile :-) It has been a long journey but one worth taking !

Healing the gut could well be the key - there is an on-line summit at the end of the month. If you are interested then I can forward the details.

Good to take a B complex when taking B12 to keep all the B's in balance. Are you supplementing B12 ? Also good levels of VitC help with the absorption of the iron. Keep the iron at least 4 hours away from your Levo otherwise the absorption can be affected.

Sorry to ramble - there are so many ingredients to mention !

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Another link illustrating some links from sleepbunny which may be relevant to you :-)


I would keep a diary of how much, of what, I eat. Then calculate (using info easily found on the Interwebs) just how much iron and B12 you are consuming. I'm pretty sure that the B12 will be way over the recommended daily amount.

That will be evidence against your deficiency being diet-related.


Thank you good idea.

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Also see if you can see someone else for a second opinion.


if you wish to take methyl then you need to inject it to gain the most benefit taking it orally if you are b12 deficient will do absolutely nothing to address the deficency


Have you had tests for parietal cell and intrinsic factor antibodies? Sounds to me like you had Autoimmune Gastritis which has now developed into Pernicious Anaemia. I'm in the same situation with low iron and trying to persuade them that this is due to Autoimmune Gastritis - it seems that this is something which is completely missing from medical training but there is plenty of research pointing out that iron deficiency is usually the first symptom - particularly in pre-menopausal women who have an extra requirement for iron.

Iron deficiency from the diet is extremely unlikely in the UK as all white flour is fortified with iron - so if you eat bread and meat you will be getting plenty. This means that unless you are losing blood, there must be an absorption problem. This is from the NHS's own website: "Unless you're pregnant, it's rare for iron deficiency anaemia to be caused just by a lack of iron in your diet."

I'm putting together some quotes while reading the research - here's some of what I've collected so far in case you are interested:

"The clinical presentation of AIG [Autoimmune Gastritis] is not associated with any specific gastrointestinal signs or symptoms. In a recent study, Miceli et al examined the clinical and pathological features leading to a diagnosis of AIG in 99 patients: the most common initial findings were hematological disorders (various forms of anemia accounted for 37% of cases), followed by a histology positive for gastritis (34%)"

"Microcytic anemia, the expression of iron deficiency, is a common presenting sign and is caused by achlorhydria, which impairs iron absorption. In a study by Hershko et al, up to 30% of patients with iron-deficiency anemia and no clinical evidence of blood loss were found to have AIG."

"The most common association, however, is with autoimmune thyroiditis (“thyrogastric autoimmunity”): more than 50% of AIG patients have circulating anti-thyroperoxidase antibodies"

Autoimmune gastritis: Pathologist’s viewpoint: World Journal of Gastroenterology (2015) 21(42) 12179-12189.

Patients with Chronic Autoimmune Atrophic Gastritis [CAAG]

"This group included 107 patients with histologically confirmed CAAG, 86 females and 21 males, aged 21–88 years, with a median age of 57.4 years. According to the Sydney classification (24), 42 patients had mild chronic gastritis, 40 had moderate and 25 had severe cases."

Chronic autoimmune atrophic gastritis associated with primary hyperparathyroidism: a transversal prospective study: Eur J Endocrinol May 1, 2013 168 755-761

(I included this quote because my histology report showed that I had mild chronic gastritis which my endo said was completely normal and in no way explained my symptoms or low iron! )

"The presence of anti-parietal cell antibodies is highly specific for the diagnosis [of autoimmune gastritis]. "

Chronic gastritis - an update: Best Pract Res Clin Gastroenterol. 2014 Dec;28(6):1031-42

(Included because I have anti-parietal cell antibodies which I've been told is completely normal.)

"The diagnostic performance of G17, PG I and PGI/II was excellent for AIG patients ..." Oxyntic gastric atrophy in Helicobacter pylori gastritis is distinct from autoimmune gastritis. J Clin Pathol. 2016 Jan 4. pii: jclinpath-2015-203405

(This is a test which your doctor can order to test for low stomach acid due to Autoimmune Gastritis)

"The test consisted of the measurement of pepsinogen I and II levels (and ratio) and H. pylori IgG antibody level in plasma by ELISA" "Altogether 3.5% (150 individuals) of all 4,256 volunteers had ACG [Autoimmune Chronic Gastritis]."

"In volunteers with ACG, the diagnosis was new in 95% (142 individuals), 5% (7 individuals) had received vitamin B12 supplementation and 13% (20 individuals) had received PPI medication according to a self-administered questionnaire; and 26% (39 individuals) reported gastrointestinal reflux like symptoms."

Prevalence of undiagnosed advanced atrophic corpus gastritis in Finland: an observational study among 4,256 volunteers without specific complaints. Scand J Gastroenterol. 2010 Sep;45(9):1036-41

(Shows how unlikely it is to be diagnosed - 95% of the volunteers who had AIG did not know even though many had symptoms of gastritis.)

Achlorhydria Medscape

"achlorhydria has been defined as a ratio of serum pepsinogen I/pepsinogen II of less than 2.9."

"In clinical conditions, parietal cell dysfunction can be induced by antiparietal cell antibodies"

"Small bowel bacterial overgrowth is a chronic condition. Retreatment may be necessary once every 1-6 months. There are reports of cycling of antibiotics to reduce the risk of antibiotic resistance. "

"Several conditions associated with achlorhydria lead to increased mortality and morbidity. Specifically, achlorhydria has been associated with the following major sequelae: gastric cancer, hip fracture, and bacterial overgrowth. "

"Irrespective of the cause, achlorhydria can result in complications such as bacterial overgrowth, intestinal metaplasia, and hip fracture. Therefore, a history of abdominal discomfort, early satiety, weight loss, bowel movement frequency, reflux symptoms, and abdominal bloating should be taken. Since acidic pH facilitates the absorption of iron, achlorhydric patients often develop iron deficiency anemia. Therefore, patients should be assessed for symptoms of anemia."

"Parietal cell antibodies are found in 20% of patients with type 1 diabetes, denoting autoimmune gastritis, achlorhydria, and pernicious anemia. "

"Antiparietal cell antibody testing should be ordered because a strong association exists between achlorhydria and so-called autoimmune conditions. If achlorhydria is confirmed, patients should have a hydrogen breath test to check for bacterial overgrowth. Iron indices, calcium, prothrombin time, vitamin B-12, vitamin D, and thiamine levels should be checked to exclude deficiencies. Complete blood count with indices and peripheral smears can be examined to exclude anemia. Elevation of serum folate is suggestive of small bowel bacterial overgrowth. Indeed, bacterial folate can be absorbed into the circulation."

"A complete profile of gastric acid secretion is best obtained during a 24-hour gastric pH study. Achlorhydria may also be documented by measurements of extremely low serum levels of pepsinogen A (PgA) (< 17 mcg/L). High serum gastrin levels (>500-1000 pg/mL) may support a diagnosis of achlorhydria."

Bacterial overgrowth: "Microecological changes are accompanied by vitamin B-12 deficiency anemia, hypovitaminosis, protein deficiency, translocation of bacteria and their toxins from the intestine into the bloodstream, emergence of endotoxinemia, and possible generalization of infection. Bacterial overgrowth is diagnosed by concentration of hydrogen in expiratory flow (glucose-hydrogen breath test) or by bacteriological study of aspirate from the proximal part of the small intestine. Antimicrobial agents, including metronidazole, amoxicillin/clavulanate potassium, ciprofloxacin, and rifaximin, can be used to treat bacterial overgrowth."

"Achlorhydria is associated with thiamine deficiency in the setting of bacterial overgrowth."

"The decrease or disappearance of parietal cells results in reduced or absent acid production (hypochlorhydria or achlorhydria) and loss of intrinsic factor. An increased gastric pH enables the colonization of the stomach by bacteria (normally deterred by the low physiological pH) that might produce nitrites and promote carcinogenesis; it interferes with the absorption of certain indispensable substances (such as iron and vitamin B12); and by continuously stimulating the gastrin-secreting cells of the antrum it induces the proliferation of endocrine-like cells in the corpus, which might give rise to neuroendocrine tumours"

"it is referred to as autoimmune meta-plastic atrophic gastritis, a condition that progresses at an unknown pace from a mild chronic inflammation of the gastric corpus to an advanced stage associated with a severe form of vitamin B12 deficiency anaemia known as pernicious anaemia."


Thank you. I will read all your useful quotes. Regarding tests for parietal cell and intrinsic factor antibodies, no I have not had them so will ask for them because I think that this will hopefully show whether I have PA or not.

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My understanding of that sentence was that there isn't a particular set of symptoms which a patient presents with which leads to a diagnosis of AIG. (May be my misunderstanding.) I definitely think that chronic gastritis in the fundus/body of the stomach along with antibodies should be diagnostic - but doesn't seem to be at the moment from my experience.


Ah, yes. They mean no external symptoms.


Yes - that would definitely be an important finding and I'd be very interested to know the outcome. I've given up taking HCl for the moment in the hope that I might be able to get a serum gastrin test.


I put several questions to my gastro team in writing and finally got them to think about it. my B12 went to 20 and I got angina. Please dont let this happen to you. There are some brilliant people on this forum whose knowledge outweighs mine. Good luck in getting yourself sorted x

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Also - did you have biopsies taken from your stomach during the endoscopy (I expect you did)? Have you asked for the pathology report to see what it actually says?


I did have a biopsy but the only thing that the consultant said to me was that it had tested negative for celiac disease. I will ask for the full report. Thank you.

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The important biopies are those from the fundus/corpus of the stomach. Mine said mild chronic gastritis. If you have B12 deficiency as well as iron deficiency I would expect your gastritis to be more obvious on the histology report.

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Any person who eats meat or fish show take vitamin B12 1000ugs because Homostyine is the toxin in meat and fish which causes strokes and heart attacks.


homocysteine does not come from eating meat or fish - it is a naturally occuring amino acid which is generated as part of the bodies metabolic processes- from breaking down methionine (an essential protein) that is vital for health. Not having enough B12, B9 and B6 means that the body isn't able to remethylate homocysteine back into mehionine.

You are correct that homocysteine causes cardio-vascular if it is allowed to build up, eg through a B12 deficiency

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Sorry that you have hit on a gastroenterologist who obviously doesn't really know an awful lot about B12 deficiency and what causes it.

There is a lot of confusion around the use of pernicious anaemia and hence some confusion/misconception that it is the only non-dietary cause of a B12 deficiency.

Given the family history and your own medical presentation it is quite likely that you do have PA but it could also be that another cause - such as lowering of stomach acidity as you get older - is the reason for your absorption problem.

Personally I think the onus should be on medics to prove that it is dietary rather than making the assumption that it isn't. It is much more likely to be non-dietary.

1% of B12 is absorbed outside the ileum (which is where absorption problems tend to occur - particularly PA -so sometimes flooding the gut with high levels of B12 - 1000-10000mcg a day can work but it doesn't work for everyone - so it may be worth trying it.

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Thanks Gambit62. Do you think I should ask to be referred to a haematologist, who will hopefully have more knowledge and experience with blood disorders in general?


B12 deficiency isn't a blood disorder - among its many consequences are blood disorders.

There are many things that can go wrong with metabolism of B12 that have nothing to do with the blood and measurement of levels in blood is only a fraction of the story.

So, personally I wouldn't recommend trying for a referal to a haemo unless you knew beforehand that they were good with B12 - ditto with gastroenterology etc.

Unfortunately it is very hit and miss as it is a very poorly understood area, despite the fact that, because of the acidity in gut reducing as you get older, it is actually a very common disorder as you get older - think over 30% of those aged in their 80s will have problems. The incidence overall is on a par with diabetes but unlike diabetes it isn't treated as a medical specialism in its own right.

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Thank you. I am 52. Do you think that the reduction of stomach acidity would start to be apparent in someone of my age? Sorry for all the questions but there is so much to learn!


50s is where the risk of B12 deficiency from lowering of stomach acidity starts to really take off so, yes, you are the right age range for that to be the significant factor


Are you in the UK?

"only thing that the consultant said to me was that it had tested negative for celiac disease"

Did you know that it is still possible to have coeliac disease with negative test results?

See link below.

Have you ever been tested for IgA deficiency? A person who is IgA deficient will not make the normal Coeliac disease antibodies.

Good luck with finding answers. I've written some detailed posts over last few months which may have some useful info if you search for them.

two useful books

"Could It Be b12" by Sally Pacholok and JJ. Stuart

What You Should Know About Pernicious Anaemia and Vitamin B12 Deficiency by Martyn Hooper


Have you spoken directly to the PAS?

01656 769 717

Office open 8am till 2pm eevry day except sundays.

One thing I have found vital is to always get copies of my blood test results especially ferritin , folate, B12 and FBC (Full Blood Count), On the FBC I look particularly at MCV and MCH, high MCv and high MCh can indicate the possibility of macrocytosis (enlarged red blod cells). See links below.

I track changes in my bloods to try to use as evidence as I remain without a confirmed diagnosis after beng highly symptomatic for B12 deficiency for many years. I had to resort to treating myself.

I ticked which symptoms I had and gave a list to my GP. See links below.


See Symptoms Checklist

"I have also been told that I may have fibromyalgia, because of longstanding symptoms of joint pain, fatigue and terrible brain fog"

B12 deficiency is sometimes misdiagnosed as fibromyalgia and ME/CFS. I've had these as possible labels and to be honest I think it's B12 deficiency and possibly hypothyroidism in my case. My experience is that having fibro or ME/CFs as a label can prevent doctors looking for further causes and that these conditions are sometimes considered to be a mental health condition by some medics.

Possible topics of interest.

MTHFR gene mutations

Dr Chandy (works with the charity)

I am not a medic just a patient who has struggled to get a diagnosis and wants people to have useful info.


Hi Sleepybunny,

Many thanks for all your good advice and I will certainly call PAS this week.


Hi everyone,

Just wanted to let you know that my intrinsic factor antibody test came back negative but my parietal cell antibody test was positive. On this basis, my GP has diagnosed me with PA. she said that the intrinsic factor test can be unreliable.

I know it sounds odd to say that I am pleased but I am. I knew that the B12 deficiency wasn't diet related, as the gastroenterologist thought and now I have proof. And I can have regular injections, which I am hoping will help. Although I am not feeling any improvement from the loading doses.

Thanks again for all your help.

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This is the thread I was referring to .... 😊

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Thank you.

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