Active B12 testing

[Alpaca24]

Hi all,

I have held off SI this month as I was trying to work out what might be causing skin flushing that I’ve been having. My neuro symptoms and stiff and achey joints are back although I’ve been waiting to hear from my GP about whether they will test for anti- intrinsic factor antibodies again and I had read injections can interfere with results. Do you think there is any point in paying for a private active b12 test (although it’s only been 1 month since no injections)? I’m not sure if it is affected in the same way as serum. I’d be curious to see if it is low and it might help my case in explaining why I seem to need 2 weekly injections. Any thoughts appreciated! Thanks

[Narwhal10]

Hi, I love your name. As no-one has replied I can only share my very limited experience. Skin flushing is common with fatigue (as is low grade fever, joint pain, swollen glands). Theses are vague symptoms of autoimmune diseases. Several years ago, I’d occasionally get a malar mask (when exhausted). It is mainly associated with lupus but a family member experiences it too and they have cancer.

Through a private dietician, I also found out that skin flushing can be due to vitamin b3 deficiency. However, without proper health professional input please refrain from supplementing. They may offer further blood tests. Lastly, there must be quite a lot of other reasons but sorry, I’ve no idea. Take selfies- photo your face in morning, evening, as a mere suggestion. You can send/show to your GP.

With regards to having a private active B12 and holding off SI for IF, I dare not hazard a guess. Hopefully, someone more knowledgeable will answer.

Best wishes

[Alpaca24 in reply to Narwhal10]

Hi Narwhal10, thanks very much for replying. I hadn't really thought about it being a potential symptom of another autoimmune disease so thanks for flagging this. I have recently realised it started 2 weeks after I started taking Pizotifen for migraine although I stopped it 5 days ago and no improvement yet but I know side effects don't always go immediately so I'll wait a few weeks and if no change, go back to my GP.

Oh yes I had heard of the malar rash connected with lupus. My flushing happens most in my palms, feet, face and ears. And I had heard of the niacin (B3) flush from over supplementing this vitamin but I don't take it - didn't realise it could also happen if you are deficient in it. I've got lots of photos of my flushing! That's actually what helped me to work out the timings with starting the migraine medication so thankfully I have documented it.

[Foggyme Administrator]

If you have neurological symptoms you should be having the intensive regime of B12 injections. That is, injections every other day until symptoms stop improving. Your symptoms are returning because you need more (not fewer) B12 injections.

Information about this intensive regime of injections can be found in the following link to the BNF (prescribing guidelines for doctors). Note - despite the BNF statement about macrocytic anaemia, please be aware that macrocytic anaemia is not always present in B12 deficiency: the absence of macrocytic anaemia should not be a barrier to receiving B12 injections, including the intensive regime for those with neurological symptoms. Here's the link to the BNF prescribing guidelines (your GP will have a copy on their desk):

bnf.nice.org.uk/drug/hydrox...

(BNF B12 Deficiency: Hydroxocobalamin Treatment Regimes)

The IF antibody test is not a reliable test - 40%-60% of those with PA test negative. The most important thing is that you're getting treatment - if you press for an IF test and it returns a negative result, your GP may withdrawn treatment in the mistaken belief that you do not have PA and therefore don’t need B12 injections (many do - and they seem to have little awareness that B12 deficiency can have numerous other causes, or that PA can still be present with a negative test, or that there’s a 'thing' called anti-body negative PA (ABNegPA) ).

If you do decide to ask your GP for an IF test this can be skewed if it’s done after a B12 injection. Different labs suggest different amounts of time for this to occur (depending on the test method used). Stated times are between 2 days and two weeks. If you leave a two week gap between B12 injection and an IF test, this will ensure that the test is not skewed by your B12 injection (whatever testing method the lab may use).

There's little point in getting an active B12 test. Once injections have commenced all the guidelines state that further testing is not required (both serum and active B12 levels can’t tell anything about the efficacy of treatment). There is a small chance that this may show low levels but the most likely outcome is that your B12 levels will be very high - probably way over the top of the reference range. If this happens your B12 injections may we’ll be withdrawn - and a low levels would likely be ignored by your GP (few will accept private tests). Again, B12 levels can’t tell you anything about efficacy of treatment or if you need more frequent B12 injections. This is why all the guidelines state treat the symptoms, not the B12 levels. In other words, if symptoms return before the next injection is due and abate once you’ve had an injection - more frequent injections are needed. The aim is to inject often enough to stop symptoms returning. When on the intensive regime and you are sure that no further improvement is taking place, the ideal is to slowly start reducing frequency until you find the right injection interval to keep symptoms at bay (unfortunately the NHS maintenance dose regime make no account of the different frequencies required by different people).

About the flushing - may be nothing to do with your B12 deficiency or you B12 injections. Could be rosacea - a potential marker of another underlying autoimmune condition - or it can occur 'alone', a 'thing' in its own right. (I get rosacea along with a Malar rash due to Lupus (an autoimmune condition) - but originally thought it was connected to B12 deficient - I was wrong 🙂. But certainly not suggesting that you have Lupus - there are many other causes of flushing).

Thinking about this and your achy painful joints (and perhaps other symptoms as well), I'd be tempted to ask GP to run autoantibody blood tests just to check if there is another underlying autoimmune condition responsible for some of your symptoms. There is a lot of overlap between B12 deficiency and other autoimmune conditions, so it would be worth perusing to rule in or out. Certainly more value in this than in asking for an IF test. If auto-antibodies are found to be present, then referral to a rheumatologist would be required for mor detailed investigations.

Good luck with whatever you decide to do.

[Alpaca24 in reply to Foggyme]

Thanks very much for such a detailed reply. Yes, I think delaying my SI this month has just confirmed to me how much I need the injections every 1-2 weeks. My GP spoke to a haematologist and they recommended against self-injecting as my "B12 is high" - this was tested by the consultant neurologist I saw. It's so frustrating that everyone seems to be clueless on this condition.

And thanks, I sent this link to my GP at the beginning and managed to get 2 sets of loading doses but then it went to 2 monthly & when I highlighted the guidelines, it was the haematologists that said I didn't need them more frequently than this. I have had the IF antibody test around a year ago and it was negative although they tested this during my loading doses. My GP has said she has left a form for me to have this test and B12 again (sigh) although I don't think I'm going to do this as I recommenced SI again as I couldn't wait any longer for her to get back to me.

Thanks for highlighting the other potential causes of the flushing. I am fairly sure the achey joints are related to the B12 as it was severe when I first became deficient and they did test me for other markers of autoimmune conditions (e.g. RA) then and all were negative. This was about 15 months ago though so maybe it's worth repeating.