Pernicious Anaemia Society
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B12 Deficiency or PA. How do you know?

Hello, I'm so glad I stumbled across this site as I actually thought I was going mad with how I was feeling (to be fair there is still a possibiity of that!) however on seeing I had the exact symptoms as so many of you , I went to the Drs and was actually delighted to be told I had a B12 deficiency. I have just finished my 1st week of injections and whilst there today asked for a copy of my results. I'm not yet sure where they are in relation to 'normal' ranges as I havent yet done my research but they look like this:

Folate - 10.2ug/L

Serum Vitamin B12 155ng/L

MCV - 92.9fL

MCH 31.8pg

RBC 4.06

Platelet 170

I have a whole page worth of others, but I dont want to send you to sleep on my first post as I am not sure which are relevant or not...

One thing I am unsure of however, is how do I know if I just have a B12 deficiency or PA? Is there something in those results that are likely to tell me? The Dr hasnt really explained the difference, but just mentioned the possibility of it being auto-immune or not. I am seeing the HCA for my injections , rather than the Dr and dont want to bombard the poor girl with my incessant questions, so thought I would do it to you instead!

Many thanks in advance

9 Replies

You have a B12 deficiency which has been caused by an absorption problem

PA is one potential cause of absorption problems - an autoimmune response that attacks either the cells that absorb B12 in the ileum - or the binding agent that helps them to absorb B12.

Other causes are: gastric surgery affecting the ileum, genetic defects affecting the ileum, drug interactions (often treating early warning signs of a developing deficiency), lowering of acidity levels in the gut as you get older.

Whatever the cause the treatment is the same. The symptoms associated with PA are the symptoms of the B12 deficiency it causes.

And your results were definitely on the low side. Your folate levels are OK but could probably do with being a bit higher ... and being monitored as they can dip when the body starts using up folate to process B12.

If you had anaemia (not an expert so can't tell from just the bare results) then you should also be monitored for your potassium levels which can also drop in early stages of B12 treatment.

Might be good to look at your diet and see if you can switch to foods that are rich in folate - as natural folate is the best forms and some people do have problems with artificial forms.


Many thanks for taking the time to reply , it is much appreciated . I had my serum potassium done & that came back as 4.3 . I was told those results were ok?

I will certainly look into folate rich foods as I would like to do everything as 'naturally' as possible . I am really thankful to have found this site though. I do believe, going in to the Dr armed with information, symptoms & a request for my B12 to be checked , stopped me being fobbed off & to be honest , this has been going on for a couple of years now . Having a conversation with me , was like playing a game of give us a clue!

Thank you again

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Sorry but I'm really not an expert on bloods so couldn't actually tell you if the potassium was okay or not but I think potassium is much more straightforward when it comes to measurement and the ranges are much clearer so if you were told it was normal then that is okay



In the US the usual normal range (sometimes called the Reference Range) for potassium is 3.5--5.0. Most lab test reports provide a reference range for each value reported, generally to the right of the result and possibly in parentheses. Also, either H or L may indicate high or low value. I've seen so many questions here about lab results I'm wondering if UK lab reports include normals?



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Your B12 is quite low. The gray area discussed in Sally Pacholok's book "Could It Be B12? An Epidemic of Misdiagnosis" is 200 - 400 pg/mL (or ng/L) and yours is below that. I recommend you purchase that book, it is available on Amazon.

You need to find out the cause of your low B12. Risks include vegetarian or vegan diet, long term use of PPIs or H2 blockers to reduce stomach acid, surgery or dental procedures that used nitrous oxide anesthesia (depletes B12), and pernicious anemia.

Your doctor should have had blood drawn to look for intrinsic factor antibodies and parietal cell antibodies as a test for pernicious anemia. You cannot have B12 shots or supplements for several days prior to the test (ask your doctor how long).


Thank you again for your replies . One thing I am wondering if anyone else has (or if it's just me) , the feeling of things crawling on you ? My legs burn/ache , which is one thing but the creepy crawly feeling makes me bust out some sporadic , dodgy moves ! I'm sure it ain't pretty !


Neurological symptoms can exhibit first in the longest nerves to the legs and hands. Pin and needles is one symptom. Burning sensation is another. If the B12D is detected early and medication started the neurological symptoms do not go away immediately.

To monitor progress, start a log book of symptoms along with food, drink and medications and vitamins.

You will begin to see a pattern of a symptom appearing up to 24 to 48 hours after a specific food, drink or medication. The delay is due to the gut being involved.

Once you understand how your body reacts, you can gain some control, eliminating the stress for worry, and have "evidence" in order to have a better discussion with your doctor.

One side effect of the b12 and the healing to the nerves is a heightened (apparent) pain or other symptoms. It takes a while for the brain to recalibrate to the stronger signals from the healing nerves.

The "dodgy moves" could be either balance issue with the nerves in the inner ear or "foot drop" where the foot doesn't seem to work properly when walking.

B12, folic acid and vit b6 work together to heal the nerves. But the progress is at a snail's pace. So see if you can determine a measurement in the severity of the symptoms and log that score also. Over time you can look back in the log book and see how things have improved if they are moving in the right direction.

Since this deficiency is a roller coaster ride, where symptoms go up and down, look at the overall results in the long term and don't try to react to symptoms in the short term. Stay with a course of medication and monitor with the log book.

You can also find additional allergic reactions by this method because the same symptom reappear x hours after eating a particular ingredient in the food. For me it was dairy, gluten, and soy.

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Results of hemoglobin (hmb) and hematocrit (hct) correlate with RBC (red blood cell count) and would be helpful in that regard. It should be remembered that anemia does not have to be present in order to diagnose B12 deficiency.


Many thanks again for taking the time to reply, everyone. I had my last loading injection today and was told to go back for another blood test in 3 months to see if any further action is required. I do feel a bit disheartened as I am worried that my levels will be higher, due to the shots and they will say that is that. In the meantime, whilst my head certainly feels a little less 'foggy' my fatigue is still there, I cant remember words, my legs feel like they are made of concrete, I have pins and needles and a recurring pain in my right shoulder (I dont know if thats connected or not).

I know I am pre-empting something that may not happen, but I am terrfied of just being left to feel like this again. I think reading is required to educate myself, just in case.

Anyway, thanks again for all of your very informed knowledge


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