Log in
Pernicious Anaemia Society
17,097 members11,841 posts

Not diagnosed but injecting b12, can I still test?

Hello all,

I have an MS diagnosis, but as primary progressive, no treatment, so nothing to lose. My FBC showed MCV 108, ferritin 8, b12 280 2 years ago. My neuro dismissed these as irrelevant, but I understand PA can sometimes be confused with MS. I started with numb toes, slowly going up my legs with tingly fingers now too. started methyl 5000 sublingual daily last year and everything 'stopped' progressing, but no real recovery either. I had 5 yeArs of diahorrea, this has gradually got better since b12 too, but again dismissed by neuro. I was wondering if I could get the Intrinsic factor test, whilst carrying on with b12 supplements. I have just started sub cut b12 1000 hydroxycobalimin from gold pharma and today, after 5 alternate days injections, I can feel my big toes!! So I don't want to stop this, so guess having b12 tests is pointless, but does the anti intrinsic antibody stay in your system despite this? Any advice welcome


6 Replies

Personally I find that an MCV of 108 can be dismissed is quite astonishing. I wonder if you had a low folate to go with the MCV.

Okay, let's make sure we are singing from the same hymn sheet:

- it is the b12 deficiency which causes the damage and the damage is dependant on how long the deficiency has been allowed to progress without being treated.

- Getting a diagnosis of PA via intrinsic factor antibodies or parietal cell antibodies is simply proving one cause of b12 deficiency. But even with this is it the severity and duration of the b12 deficiency that is the important issue.

- B12 deficiency does not start with anaemia, it progresses through to anaemia. The neurological damage comes first.

- Unfortunately the serum b12 test appears to be set up to identify when the patient has anaemia - which is a little late in the course of the illness.

- If you have gone on long enough then some neuro damage is permanent (particularly where nerve heads die) and no matter how much b12 you have it cannot be rectified.

- Even if you had the tests and even if they weren't affected by supplementation (which they are) you will not convince your neuro of anything because they clearly haven't been convinced up to date and will only give you treatment to reverse the final stage of the illness.

So, whether you have IFA or PCAs is irrelevant. If you have another b12 malabsorption problem the cause of which hasn't been identified, you may be slightly better off in that you can treat it if you identify it.

In many ways you have answered your own questions - you appear to be improving matters on your own. How important is it to you to convince the medics? And that is a genuine question.


1 like

Hello and thank you to everyone has replied.

I do realise that a diagnosis of pernicious anaemia, if that is what I have, Is much less important than my health improving. But, a diagnosis of primary progressive MS, is a big thing and not a good thing;I would much, much rather have subacute combined degeneration as, whilst damage done is not necessarily curable, with B12 injections progression is no longer a certainty.

I took the first neurologists opinion, who patronisingly agreed to test my B12, then dismissed it all, as, "he who knows better".

MS specialist neurologists do not appear to agree that neurological affect can happen before haematological changes,even though now, I now understand I had some of those indicators too.I did try, in June I specifically pointed to my MCV test and he just said that's just an anomaly.So, thanks to the information here I'm going to carry on with the injections for the BNF recommended three weeks and see what happens. Since my first post, my legs feel really warm wherever they are numb. I've been taking D3 for a year My neuro's recommendation and the usual multivitamins etc so the only thing that's changed is bypassing my digestive system with the B12, faster and more than the 1-2% passive absorption. We shall see!


I think you will find that MS neurologists are going to have to smarten up in the very near future. They can't rule out b12 deficiency if they don't understand it. Simple as that.

They might not 'agree' that neuro effects happen first but there is a little thing called biochemistry that would beg to differ.

If it makes you feel any better, in the US today one of the top 5 malpractice lawsuits comes from patients who were diagnosed with MS but who actually had b12 deficiency.

You aren't harming yourself with the B12 (although the BNF guidelines are terrible when it comes to treating for neuro damage) so I guess in this case, like with many of us, you have to take into consideration what the doctors say but establish if they are correct by doing your own research.

I'm very glad things are improving a little for you!


Hi Sian,

B12 can help in MS patients see:


Vitamin B12, demyelination, remyelination and repair in multiple sclerosis

More info in this old PAS topic:



B12 can do no harm, but possibly a lot of good so stay on it, and the IF test is not terribly reliable anyway, people with PA have tested positive, then negative so not worth it.

I hope this helps you,

Kind regards,



Have you also been tested for VitD ? vitamindcouncil.org and click onto Health Conditions at the top of the page. Low levels are at epidemic levels and are linked to many chronic conditions....

Glad the B12 is working for you....


PA isn't the only absorption problem that can lead to a B12 deficiency, so you'd just be ruling out one possibility without actually being able to prove that you have a B12 deficiency so agree with Marre that probably isn't worth pursuing it now but if the B12 is helping you then continue with it

- glad that you can feel your big toes again.


You may also like...