Pernicious Anaemia Society

Anaemia because of B12 Deficiency

This may be a silly question but it comes from an appt just had with GP. I've managed to keep my jabs every 8 wks whoop! Thanks to info from site, thanks everyone- I went armed with highlighted BNF.BSH info.

Doctor asked me why I became Anaemic in first instance as this was first indication that something was wrong! I had assumed it was because of B12? As I went onto be diagnosed with PA (instrinsic factor positive result)?

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Hi SarahFerguson was you doctor asking why you had Pernicious Anaemia or iron deficiency anaemia.

Have you had your Folate level checked recently?


Hi Clive, she was asking why I became Anaemiac in first instance. Asking if I had bleeding from heavy periods/diet/bowels, None of these relevant as had a few tests done and all came back ok, so she was trying to work out why Anaemic! My ferritin last checked in 2015 was 37 I think my folate was satisfactory but bottom end! I haven't had colonoscopy or endoscopy.


As I understand it the word Anaemia in P.A. is misleading and often gets confused with being iron anaemic because of a similarity of some of the symptoms.

Perhaps P.A. would be better described as "Pernicious deficiency due to inability to absorb B12" a.k.a PDDTITAB12 :)

I think we'd better stick to P.A.

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Hi Clive , still confused! What I'm trying to understand is : could there be another reason other than PA for being Anaemic? My diet is normal!


There are lots of reasons for anaemia. See the table at the bottom :

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Thank you human bean. So, is it possible to need Iron supplements aswell as B12 injections running along side each other. ? I'm taking Ferrous gluconate everyday, aswell as jab every 8 wks due to PA.


Yes. It is perfectly possible to have iron deficiency and B12 deficiency in the same body and need to supplement both.

The only thing is, iron must only be supplemented if it is necessary. Too much iron in the body is poisonous and there is no obvious mechanism for getting rid of the excess. So frequent testing is necessary to make sure that supplementing doesn't go too far.

People who absorb iron too readily because of a genetic fault (hemochromatosis) deal with the problem by giving blood.

Some useful links :


I am not a medically qualified person but The Mayo Clinic says:-

"Slow, chronic blood loss within the body — such as from a peptic ulcer, a hiatal hernia, a colon polyp or colorectal cancer — can cause iron deficiency anemia. Gastrointestinal bleeding can result from regular use of some over-the-counter pain relievers, especially aspirin. A lack of iron in your diet".

And this is a link to NHS Choices

I hope this helps

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Hi SarahFerguson. Just a quick comment...

People with B12 deficency and or PA often have absorption problems...

The absorption problems can lead to a range of deficiencies, the most common being iron deficency anaemia. Folate and vitamin D deficeny are also common, as are others.

In addition, people with PA most often have an absence or lack of stomach acid which makes it difficult to absorb iron. Taking iron supplements an hour before food with orange juice or lime juice can help with absorption.

Ferritin levels need to be good for iron to be absorbed properly (iron binds to ferritin so that it can be absorbed by the body). Ferritin levels need to be in the mid to top third of whatever the reference range is for optimal benefit.



Retren26Jan you are so knowledgeable long time since I read your posts but did ask a while back how you became an a,Have been struggling meantime with various problems.Happy New Year somewhat belated.

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