Pernicious Anaemia Society
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B12 Deficiency - advice needed!

Apologies for the long post...

I am a 35 year old female, and about a year and a half ago I had iron-deficient anaemia. I was treated with iron supplements and my iron levels are now ok. However, I have felt utterly exhausted over the past 6 months (no matter how much I sleep) and have been suffering with poor memory, confusion, lack of concentration, regular ‘brain fogs’, headaches, dizziness, palpitations, shortness of breath and general feeling of nausea. I assumed the anaemia returned (or I was just loosing my mind!) so asked my GP for a blood test.

The results came back, and my iron levels were fine, but my B12 levels were low:

Transferrin saturation index: 24% (range 16-50%)

Serum iron level: 16.5 (range 11-30)

Serum ferritin: 19 (range 10-200)

Haemaglobin estimate: 125 (range 120-150)

B12: 127 (range 180-900)

I read the information on the NHS website and and felt an enormous relief that there seemed to be an explanation for how I was feeling, as my symptoms seemed to match those of B12 deficiency. I also read many case studies where levels of around 127 were considered very low, and patients experienced similar symptoms to me.

I saw my GP last month to discuss my test results. I was told that they were all normal. When I questioned the B12 result, she said my B12 levels were slightly low, but that “we are all a bit deficient in some vitamin or other”. When I asked if it could be the low B12 that was causing my symptoms, I was told no, and that I probably had post viral fatigue syndrome. When I said “But I haven’t been ill!” I was then told that I must be depressed (I'm not). She said there wasn’t any point in further testing for pernicious anaemia, because my blood test shows I’m not anaemic. The GP recommended I take multivitamins (which I already do, and have done for years). I was fairly desperate, so asked her outright if I could have B12 injections and she reluctantly agreed.

I finished the 6 loading doses last week. I felt no different for the first few days, but towards the end of the two week period started to feel like I had some energy again and didn't experience any brain fogs. However, in the last 10 days since my last loading injection, I am back to feeling exhausted, confused and very 'foggy'. I'm supposed to wait 3 months before the next injection.

Does anyone have any advice? Specifically:

- Should I see a different GP to discuss this problem? 127 is surely lower than it should be, and surely could be the cause of my symptoms (particularly as they did start to ease when having the injections)? I don't want to appear a hypochondriac, or like I'm telling the doctors what to do!

- The GP agreed to the 6 loading doses, but should I ask for more? The NICE guidance for pernicious anaemia suggests that where neurological symptoms are present, you should continue with the injections every other day until symptoms stop improving, with possible referral to haematologist or neurologist . Do the confusion, brain fogs, memory loss and headaches count as neurological symptoms? Do these rules apply even if a person isn't anaemic?

- Why would my B12 levels be low? Is this pernicious anaemia (even though I'm not apparently anaemic)? I do have psoriasis which is another auto-immune condition, but am otherwise healthy, eat a good balanced diet, with plenty of meat so why wouldn't I be absorbing B12?

Sorry again for the long post, any advice would be welcome.

13 Replies

My understanding is that all the symptoms you are displaying are neuro symptoms and therefore you should have been given a loading dose every other day until there be no further improvement. Whether you have PA or not is really academic, you have low levels, well below the reference range and need to get injections. It is a commonly held misconception that you need to be anaemic to have PA. NOT SO. To add a further layer of confusion, the serum blood test is very unreliable because it only shows the level of ALL the B12 you have in your blood, it doesn't tell you what level of Active B12 you have, that is, how much you actually have beavering away in your blood cells. Write to your GP or better still, go see him/her again with a copy of the BCSH guidelines and a list of likely symptoms which I think you should be able to source from this site. I only have a PDF file for the BCSH article and the BMJ article which is also informative and helpful but hopefully another poster here will put up the links for you.

As for why you may have PA, you could have inherited it, you could have had a serious stomach problem that destroyed the parietal cells in your stomach lining, you may have had bariatric surgery, there are a host of reasons. The important thing is that current guidelines state that if your symptoms atest to B12 shortage you should be given treatment without delay and that NO further blood tests should be done because they will forever show artificially high levels as you try to ensure you have enough in the hope of getting at least some to your poor blood cells.

Keep at it, go back to the GP, whenever you feel the need, make your problem high profile, print off the articles, once you have been given the links, and don't give up! If all else fails you can get advice here on how to source the necessary B12 and supplies to self medicate.

Finally, point out to the GP that if your body were able to absorb B12 in the normal way, why aren't the multi vits you are taking giving a higher level? Why are you still at a lower than range level?

If you get referred to a haema take copies of the articles with you there too, I'll bet you can guess why!

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Unfortunately your GPs levels of ignorance when it comes to B12D and pernicious anaemia are far from unusual.

Pernicious anaemia is one cause of B12 deficiency - and it is the B12 deficiency that can lead to anaemia but anaemia is a symptom not a defining characteristic. The name is pernicious anaemia is a bit misleading. Medics would argue that the pernicious is misleading because it implies a fatality that isn't the case this year - personally, given the way it gets mistreated - including people not getting treatment as frequently as they really need and ending up in a 'living death' - I think the pernicious is probably still spot on.

Because of fortification of foods with B9 (folate) many people don't exhibit signs of anaemia but develop neuro problems first these days. Your folate levels are good increasing the possibility that your problem has been going on for some time.

B12 deficiency can be caused by by lack of B12 in diet (eg strict vegan with no dairy or fish - or low levels of meat, dairy and fish. However, absorption problems are much more common. These include

- pernicious anaemia - an autoimmune response that attacks either the binding agent that allows B12 to be absorbed, or the cells in the ileum that do the absorption, or both.

- low stomach acid - something that tends to get worse as you get older

- gastric surgery affecting the ileum

- genetic abnormalities affecting the ileum

- drug interactions including treatments for acid reflux (omeprazole), metformin (used to treat type 2 diabetes), some antihistamines, some anti-convulsives (eg Gabapentin), NSAIDs and a whole hoste of other

Drug situation is particularly complex as many of the drugs are treating symptoms that could be early signs of B12D so end up making the situation worse.

This is link to a list of B12 symptoms which is somewhat fuller than the NHS link


If you have neurological symptoms then the protocal would be shots every other day until improvement stops and then shots every 2 months.

Unfortunately lots of people find that the timescales provided for maintenance shots really don't work for them.

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Yes all your symptoms could very well be due to B12 deficiency. After reading up the guidelines I would suggest going back to the GP with someone supportive, a record of your symptoms in diary format showing an increase in symptoms and a copy of your research. See if they will increase the frequency of injections.

If not many people either self-inject or use nasal/sublingual. It may well be a battle but it is your health. Be assertive.


I'd give the PAS (Pernicious Anaemia Society) a ring. Head office: 01656 769 717


It is depressing that your B12 is so low with obvious neurological symptoms and GPs are still ignoring the latest guidelines and research. This link gives advice on writing to your doctor with useful templates. Also an excellent film:

You could also include the link below and summary of the latest BMJ research document, (if GP won't read the full document) which gives advice on further tests and when to refer to specialists.

Cmim/BMJ document. " Summary:

* Vitamin B12 deficiency is a common but serious condition

* Clinical presentation may not be obvious thus leading to complex issues around diagnosis and treatment.

* There is no ideal test to define deficiency and therefore the clinical condition of the patient is of utmost importance."

* There is evidence that new techniques, such as measurement of holotranscobalamin and methylmalonic acid levels seem useful in more accurately defining deficiency.

* If clinical features suggest deficiency, then it is important to treat patients to avoid neurological impairment even if there may be discordance between test results and clinical features.

Severe deficiency shows evidence of bone marrow suppression, clear evidence of neurological features and risk of cardiomyopathy.

*It is important to recognise that clinical features of deficiency can manifest without anaemia and also without low serum vitamin B12 levels. In these cases, treatment should still be given."

"If there are neurological disturbances, then treatment should be expedited and started without delay - 1,000 u.g. i.m. on alternate days. This should be continued for up to three weeks or until there are no further improvements.

In irreversible cases, e.g. P.A., the treatment should be continued for life. "


'Early treatment may prevent devastating complications':


Autoimmune conditions are often interlinked and avoiding gluten seems to help many autoimmune problems. It may be that you are unable to absorb nutrients, including B12.

Having done all you can to get the information to your GP, the reality is that you need to supplement your injections as there is a short window of opportunity before neurological symptoms become permanent. All of the above could take time so it might be as well to look into self medication - injections (lots of advice on this site) as well as supplementing with sublingual sprays or tablets (Jarrow's Methylcobalamin 5,000 and 10,000 mcg. are available from Amazon and seem to work well for many people) - good reviews for neurological symptoms.

Very best wishes for a good outcome.


Make a formal complaint to the PHSO .


It might be interesting to look at the management guidelines for B12 deficiency in your county/area's NHS and see if they follow BNF/NICE/BCSH guidelines.

Google "your county NHS" and then put "management guidelines B12 deficiency" in search box.

If you can't find it. then you could submit a FOI (Freedom of Information) request. Details of how to, will be on the NHS website.

You could contact your county/area's CCG (Clinical Commisioning Group) and ask if the NHS in your area is following the latest BCSH guidelines.

People are very individual as to their needs for B12. I am aware of people who are fine on every three months to people who take multiple doses every day.

Apart from one set of loading injections I never received any other B12 from the NHS. I had multiple neuro symptoms at the time I got loading injections.

In an effort to be fair to GPs, I think the problem is lack of training.


i think lack of knowledge is part of the problem with b12d. however, the other part of the equation is 'nurse injection' time.


Thanks all for your helpful replies. Its so good to know that I am hopefully right in thinking that more B12 injections might be the way forward. I have booked to see a different GP (but no appointments available for 2 weeks, so another 2 weeks of feeling grotty) so will go armed with the printouts you all suggest and bracing myself to be strong and ask for what I need.

As for the reason why its happened - I am not vegan/vegetarian, and eat what I consider to be a relatively healthy and balanced diet. I don't take any other medications, and have never had stomach surgery. The only thing that's changed in recent years is that I had a planned C-section with my second child 2.5 years ago. Does anyone know if this can cause you to stop absorbing B12?!

Thanks again - its been really useful to have your advice and support


If you had any nitrous oxide (laughing gas) then that inactivates B12. Having been pregnant depletes your B12 as it goes to the baby. Breast feeding also uses up B12. It would be worthwhile considering getting your toddler tested. Sally Pacholok talks about the possible impact B12 deficiency can have on developing babies/breast feeding babies in Could it be B12? B12 deficiency does not develop overnight. I don't mean to frighten you but it is important to consider. Most of the serious cases she mentioned seemed to be related to vegan mothers who breastfed though.

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Found this about nitrous oxide and B12 deficiency.


Whoops, link doesn't work. You could go to website and put "nitrous oxide B12 deficiency " in search box.


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