B12 blood results low: Hi all, I went... - Pernicious Anaemi...

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B12 blood results low


Hi all, I went to the doctors due to feeling exhausted all of the time, constant headaches, memory loss, a feeling of swallowing something in my throat, constant cough amongst other things. Doctor booked me in for the next week for various blood tests 20/03/18. I rang for results and was told dr wanted me to make appointment due to B12 result but it was not urgent, booked 16/04/18. I will put my other results in the comments. Are these results not urgent or should I be demanding to see doctor earlier?

4 Replies

your serum B12 is very low. I am assuming you are not a strict vegan (ie that you do have B12 in your diet). This makes a dietary deficiency unlikely and you really should be started on B12 shots sooner rather than later. It may be that your blood work isn't showing signs of macrocytosis (larger rounder red blood cells than normal) and your IFA came back as negative so your GP is mistakenly thinking that your B12 status is not that bad and you don't have an absorption problem. If this is the case please make sure your GP is made aware of the folloiwng:

a) macrocytosis is a symptom of B12 deficiency, not a defining characteristic and is not present in 25% of people presenting with B12 deficiency

b) the IFA test is not very sensitive resulting in false negatives 40-60% of the time depending on the exact test method - which means it is a long way from ruling PA out as a cause.

Source for this is the BCSH guidelines on diagnosis and treatment of cobalamin and folate disorders which can be accessed here if you are UK based,


your GP can access through the BNF.

Please also make a full list of your symptoms


if you have neurological symptoms - some count tiredness but usually it's down to whether you have any tingling/numbness in hands/feet/legs - there is a more aggressive treatment.


Carlaco in reply to Gambit62

Thank you for your prompt reply Gambit62.

My IFA - 0.94 u/mL

Serum ferritin - 43 ug/L

Serum folate - 6.7 ug/L

Eosinophils count - 0.44 10*9/L this came back with a high lighted star the same as the B12 test.

I shall look at your information recommendations.

Your GP's delay in treating you is putting your health at severe risk for, as you probably already know, B12 as low as yours can cause many symptoms, including severe fatigue, neurological problems, etc that should be treated , "every other day until no further improvement", as per British National Formulary".

Adequate treatment with injections from the outset is essential to avoid permanent neurological damage and many doctors fail to realise the importance of this:


“In the event of any discordance between clinical findings of B12 deficiency and a normal B12 laboratory result, then treatment should not be delayed. Clinical findings might include possible pernicious anaemia or neuropathy including subacute combined degeneration of the cord."


Also, latest BMJ research document summary only - GP will probably be able to access the whole document (behind a paywall):


"What are the clinical features of vitamin B12 deficiency?

"The clinical manifestations of vitamin B12 deficiency (fig 2⇓),3 5-7 9 13 represent the effects of depletion on multiple systems and vary greatly in severity. The clinical manifestations are heterogeneous but can also be different depending on the degree and duration of deficiency.

Mild deficiency manifests as fatigue and anaemia, with indices suggesting B12 deficiency but an absence of neurologicalfeatures. Moderate deficiency may include an obvious macrocytic anaemia with, for example, glossitis and some mild or subtle neurological features, such as distal sensory impairment. Severe deficiency shows evidence of bone marrow suppression, clear evidence of neurological features, and risk of cardiomyopathy. However, 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 without delay."


This document also stresses the importance of early treatment :


"Early diagnosis is essential if treatment is to be effective, for the reversibility of neurological symptoms is largely dependent on their duration. The brain lesions which form part of the neurological syndrome of vitamin-B12 deficiency, although they have been recognized for more than half a century, are still much less familiar than those which occur in the spinal cord and peripheral nerves, to which by long usage the term “subacute combined degeneration” has been applied.

And in 1960 The British Medical Journal published A.D.M Smith - "the necessity for making the correct diagnosis cannot be overstressed, as delay is extremely dangerous and the condition eminently treatable, provided cerebral demyelination has not occurred.”


Here is a very helpful site with list of B12 def. symptoms and templates for writing to your GP to ask for urgent treatment and perhaps take someone close to next appointment for extra support.


Very good wishes Caraco for much better treatment......

Carlaco in reply to Polaris

Thank you for your reply Polaris , and I will go to the doctors armed with information on relevant treatments etc and not be fobbed off.

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