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Pernicious Anaemia Society
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Six months off all forms of b12

Hi I’ve been off all forms of b12 for six months now and got a serum b12 of 241pmol/l and an active b12 of 127 pmol/l on 21/11/17 (its 9/12/17 today).

Does this mean I’m not b12d?

I began self injecting back in April but had to stop due to developing awful anxiety after each one and then some very negative thoughts. I’ve been feeling much better and had returned to work but these last few weeks a few in my original symptoms have crept back in and I’m very tired by around 5pm.

10 Replies


I'm not medically trained but from my own experience know that it is possible to have the symptoms of B12 deficiency with a B12 result that is well within range.

Your MCV is fairly close to top of range 96 (80 - 99 fl)

Your MCH and MCHC are both above range.

RDW is at bottom of range.

Link below about results on Full Blood Count (also known as Complete Blood Count).


Link about macrocytosis


Might be worth seeing if doctor would order a blood film, also known as blood smear as this hopefully would show any unusually shaped blood cells.



Link about being symptomatic for B12 deficiency with an in range B12 result (mainly UK info).


Misconceptions about B12 deficiency


BSH Cobalamin and Folate Guidelines flowchart


Indicates that if a person who is symptomatic for B12 deficiency with normal range B12 (with other diagnoses excluded) responds to b12 treatment then a continuation of treatment should be considered even if second line tests such as MMA, Homocysteine and Active B12 are normal range.

BSH Cobalamin and Folate Guidelines


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you MCH is high - implying that your red blood cells are rounder than they should be - this makes them less efficient at transferring the oxygen they are carrying. MCHC is a ratio that involves MCH which is why it is also elevated. This is a classic symptom of macrocytic anaemia which, in turn is a classic symptom of B12 deficiency

I'm afraid I can't remember what your levels were like before you stopped supplementing.

I also can't remember what your relationship with your GP is like but I really would recommend discussing the results with your GP - I'm assuming that the results were private - they may want to repeat the test - and if that shows a further drop in levels then that would also point to an absorption problem.

In general the ratio between active B12 and serum B12 is about 20% but yours is much higher than this - not sure if that would be significant or not


Have you had a blood film performed? High mchc can be indicative of hemolytic anaemia. My son has high mchc and low neutrophils and is under investigation for autoimmune hemolytic anemia. Blood film and direct antibody test are useful to diagnose. Also a reticulocyte count would be useful as haemoglobin can be “normal” with hemolytic anaemia if the body is compensating well.

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Hi again,

Just noticed that your neutrophil levels are only a bit above lower end of range.

I do not know if this is significant.


To answer your question, Your bloods show your not B12D now. However, if you have PA, without continued injections, you will become B12D in time.

I injected weekly for 2 years. When I lost the courage to inject (may sound stupid but real to me), went 20 months before PA symptoms returned.

My layman's understanding is, excess B12 is stored in the liver. When injections stop, B12 from the liver is used to maintain B12 levels in the blood until it runs out. That's when you become B12D.

It's your choice to resume injections or not. But, as your health declines and you seek medical assistance, some doctor will order an injection (or series of them). The only real question is, what damage will your body have sustained by then and can it be reversed?


They left me at least five years untreated sadly after a blood test in 2012 came back at 146pg. In 2008 I have a 250 on file. I think I’ve been low for a long time and am struggling to get better now.


How often did u inject ?

Do u knw the total no. of injections you had before stopping.

Do u knw what yourlevels were before you started injecting ?


I had one injection from the nurse then after ten days I self injected and ten days later I self injected again. Prior to injecting I’d gotten my b12 serum up to around 700 on sublingual b12.

My initial level pre b12 in 2016 was 153pg but I had a 146 pg on file from 2012 that I didn’t know about. They left me for at least five years without treatment.


Thanks for your reply.


Please see my posts. Keeping u, and all in my thoughts and prayers. Ox ..


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