Pernicious Anaemia Society
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Bit B12, thyroid or something else?

Hello everyone,

I've been having symptoms the last few months of palpitations/racing heart, freezing cold or burning feet and legs, numbness on and off in feet/hands, random twitches, feeling eyes are difficult to focus, tired (walking up small slopes - usually I hike in the mountains with no problems), feeling of unbalance at times, foggy/lack of concentration, a couple of near fainting episodes.

I've now had a few rounds of blood tests but am not much further along, can anyone shine any light on my results please as the doctor just seems unable to - all 'normal/within range':


Haemoglobin 131 g/L Range: 115.0-165.00/L

Total White Cell count 7.40 Range: 3.40-11.00

Platelet Count: 398 Range: 140.00- 450.00

Haematocrit: 0.414 Range: 0.35- 0.47

RBC count 4.26 Range: 3.90 - 5.60

MCV: 97.2 Range: 80.0 - 102.0

MCH: 30.8 Range: 26.00 - 32.00

MCHC: 316 Range 300.0 - 360.00

Red Blood Cell distrib width: 13.1 Range: 11.00-16.00

Neutrophil: 4.90 Range: 1.70-8.00

Lymphocyte count: 2.00 Range 1.00-4.00

Monocyte: 0.40 Range:0.20-1.50

Eosinophil: 0.10 Range: 0.00-0.50

Basophil: 0.00 Range:0.00-0.10

HbA1c level: 30mmol/mol Range: 21.00-42.00

Serum TSH: 3.2 Range: 0.27-4.20

liver Function

Serum total bilrubin level 8 umol/L Range: <21

Total Alkaline phosphatase 42 Range: 30-130

AST serum level 16 Range; <32

Serum albumin 45 Range 35.0-50.0

Renal profile

Serum Sodium 140mmol/L Range: 133.00-146.00

Serum potassium 4.0 range; 3.50-5.30

Serum creatinine 53 Range: 44.00-80.0

GFR calculated abbreviatd MDRD >90 mL/min Range: >60mL/min

Serum 25-HO vit D3 level 75 nmol/L Range:<30 severe deficiency, 30-70 borderline insufficiency, 70-200 replete

B12/folate level;

Serum vitamin B12 254 pg/mL Range 180-914 pg/mL

Serum folate 14.3 ng/mL Range 3.10-20.00ng/mL

Had ECG, showed normal. Had Holter monitor and waiting 2 weeks or results

So I thought the B12 looked a bit low (and I am vegetarian and symptoms could fit) so managed to get referral for Active B12, MMA and homocysteine at Viapath, St Thomas, had a couple of weeks ago.

Only the Active B12 has come back at 120 ! Range >70

There has been a problem with the analyser at St Thomas for the MMA so it won't be back till sometime next week. The Homocysteine result they forgot to send, so are sending today apparently. I questioned my Active B12 result because it seemed so high when i was pretty low in the range of Serum B12 and also was dated 2 days before I went to get my blood taken at St Thomas, but they said its correct and that it was mistakenly dated the date of my referral letter.

Can anyone help at all, starting to feel like I am going mad and that the dr is looking at me like a hypochondriac!

Thanks in advance :)

32 Replies

Forgot to mention pains in calfs, and chest tightness, sometimes I need to take an extra big breath....the list goes on!


Hcmax, TSH 3.2 is a sign your thyroid is struggling to produce sufficient hormone. Unfortunately NHS doesn't usually diagnose or treat hypothyroidism until TSH is over range (4.20) even though symptoms can precede abnormal bloods by months/years. Ask for thyroid function to be retested in 6-12 months.

I'll leave the B12 and other results for others to comment on.


Hello Clutter, thanks very much for your reply (sorry I'm learning to use this site and had commented below but didn't realise you wouldn't see it unless I directly replied). It is really interesting that to see that 3.2 may be a signal & once I have the other current tests back (MMA, homocysteine, ferritin and holter monitor) I shall look into paying for further thyroid tests - would wider thyroid tests make a diagnosis? or would it be pointless until the picture is more pronounced in my TSH blood result?


Hcmax, TSH is a pituitary hormone and doesn't give much of a thyroid picture and always misses diagnoses of secondary hypothyroidism which presents with low-normal TSH and below range FT4 &/or FT3.

Ideally, TSH, FT4, FT3 and thyroid antibodies will be tested. TSH is highest early in the morning and before food and drink (other than water) so arrange fasting tests early in the morning in future.

Private tests can be ordered via Blue Horizon and Genova via Post results with the lab ref ranges on Thyroid UK and members will advise.

You're unlikely to get a NHS diagnosis and treatment until either TSH is over the NHS GP's lab range or FT4 is below it.


Your B12 is in the grey area in the serum test - where people can have significant clinical signs of B12. One problem with the serum test is that it looks at all B12 and not just the forms that are used at the cell level - the active test gets round this problem but doesn't actually tell you what is happening at the cell level where problems can also occur, so although better it is still not an absolute guide.

If you have good quantities of dairy products then you should be getting enough B12 in your diet and your folate level is good so that wouldn't appear to be a problem (body needs B9 (folate) to process and use B12 efficiently.

Going to assume that if B12 is the issue then it is an absorption problem rather than lack of B12 in your diet. 99% of the B12 you absorb is absorbed through the ileum. The body also stores and recycles B12 quite efficiently - store in liver, release in bile back through the ileum. If you have an absorption problem then it can take a significant amount of time to become a deficiency (years or even decades) as a result, but will tend to accelerate towards the end because the recycling mechanism becomes very inefficient.

Generally the recommendation is to try and get a definitive diagnosis before supplementing as supplementation makes a proper diagnosis nigh-on impossible.

1% of B12 is absorbed outside the ileum so it is possible to flood the gut with B12 in large enough doses and enough gets through - though this doesn't work for everyone - you'd need to take around 1mg a day at least. Good news is that B12 isn't toxic so not a problem to have high doses. You could also try sublinguals or nasal sprays or skin patches (using other membranes to get B12 into your body) - though they don't work for everyone.

However, on the whole I'd be inclined to think that it probably isn't B12 - but something like thyroid that has a huge overlap in symptoms with B12 ... however, the option of trialing B12 for yourself is always there, if you can't get any further with the doctor.


Gambit62, thanks for all your insight and info. it sounds like I need to hang on and wait for the other tests to definitively rule B12 in or out for certain and then look for another cause (and possibly take B12 supplements to give it a boost regardless). I'm still confused as to how my serum could appear at the lower end of normal (254) and the active be 120 which is pretty high but I suppose I could have not a great deal but be good at converting it/using it? I have been vegetarian for over 7 years and have started eating meat in the last couple of weeks as i have been craving it and am unsure if its making any difference or not but I suppose it would be too early to tell.


Thanks very much Clutter and Gambit62. its great to have your insight.

Clutter - would it be worth paying for other thyroid tests privately (my NHS dr doesn't want to do anything other than TSH as it is in range) - or are the other tests not likely to show anything further?

Gambit62 - Very interesting info, I guess I will wait it out for the homocysteine and MMA and then hopefully that will be a conclusive picture of my B12 situation. Then could do some supplementing to bring up B12 and vit D (which is OK at 75, but not massively high given its summer and I spent last winter in a sunny country).

The only other random think that has occured to me is Lyme Disease. I got a tick on me when mushroom picking last October in Sweden and didn't find it for more than 24 hrs (it was small and behind my knee). Anyone any experience of Lyme disease and my symptoms or would my blood tests above be showing something?

Thanks very much, I really appreciate it.


I think it would be good to have in depth thyroid testing. It can be done privately and there is good information on the main website of Thyroid UK. I would suggest the TSH - FT4 - FT3 -Anti-TPO and Anti-Tg - the last two being thyroid anti-bodies. Hashimotos is the most common of thyroid conditions. You will also receive a report which you can show your Doc. You need to know if your Thyroid is producing enough T4 and whether or not it is converting into the Active T3.

Low B12 and Thyroid seem to go hand in hand....

Clutter would not have received your reply - I just came across this thread randomly so am doing my best on her behalf ! Replies only go to people when you click onto the orange Reply button after their post.

Hope you soon have some answers :-)


thank you very much Marz, and thanks for the heads-up that my replies wouldn't have been seen, as i've just started using the site. Would it be likely if I were to pay for private testing that the other things could show something deficient enough to warrant treatment or would my TSH be well out of range if this was the case? After paying for the active B12, MMa and homocysteine, I am a little concerned if things show but are still normal enough that no one would treat me?


hcmax - am afraid that is the unknown bit ! It might be more clarification for you though. I had in range TSH - FT4 - FT3 back in 2005 when I was diagnosed - but the high anti-bodies clinched the diagnosis and treatment began. When you have the results you could post them on the Thyroid UK part of HU and people will comment. Clutter is an Admin there and there are lots of us from Thyroid UK here on the PAS forum - oh have just seen her reply to you above...sorry am repeating things :-)

I think we have to do as much as possible for ourselves to solve the mysteries of underlying conditions - rather than allow ourselves to be treated for the various symptoms :-)

I would also have the Ferritin - Folate - Iron - VitD tested. These are all needed to be OPTIMAL for you to feel well. Low iron can cause you to feel tight/breathless too. Magnesium - do you take it ? Apparently most of the world is deficient and helpful for so many mechanisms in the body....


I think you are right, I'm just going to have to get everything checked even if is just useful by way of ruling things out!

I'm waiting for the Ferritin results (hopefully back tomorrow), my folate was in the higher end of the range (14.3) Range 3.10-20.0. Vitamin D was 75 (over 70 replete). What is the iron test? Is it above in my FBC? I asked when I asked for Ferritin on monday if that was the only iron test I needed and he said that was all...?

I tried taking magnesium when this all started and it worked sometimes in calming the palpitations but not always and I stopped taking any supplements when I started getting tests as I didn't want to throw them out in any way but I will bear it in mind for the future. Thank you very much for your help.


Apologies - I should have re-read your first post ! I think when you have the Ferritin result you will know a little more. If Ferritin - the stored iron is low - then I think it's safe to presume that circulating iron will be low !


no probs, there is so much info on here with everyone's results and my post was very long!!! Okay so fingers crossed the Ferritin might give some clues :)

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Thanks, Marz :)

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Are you in the UK? My impression is that Lyme Disease is another condition that like PA is somewhat neglected in the UK.

The HPA (Health Protection Agency) lyme test is not foolproof. People can test negative and still have lyme. The HPA has been replaced by Public Health England.

If your GP is willing to order the standard test for lyme then make sure they know and write down which country you were bitten in. The species of borreliosis vary from country to country.

Other nasties besides borreliosis can be transmitted through a tick bite. There are few doctors who specialise in lyme in the UK.


Hi Sleepybunny, yes I am in the UK and I haven't fully looked into Lyme yet as I read so much about B12 deficiency fitting my symptoms I think I was hopeful those blood tests would be conclusive and I could get on with treatment. Plus being diagnosed and treated for Lyme looks like such a minefield! i will look at those links, thanks very much. I haven't even mentioned to the Dr. about the tick bite/Lyme for fear of being branded neurotic, as it is I've only been feeling this way a few months or so (noticeably) and feel like all of the blood tests so far are just proof to them there is nothing wrong and I should just go away. I'm already tired of pushing and them making me feel its all in my head. Although hours of heart at over 100bpm yesterday evening whilst sitting having dinner, sitting on a train then lying in bed tells me otherwise! (amongst other things but its the palpitations that bother me most).


Hcmax, I know nothing about Lyme but this was posted yesterday


Thank you, thats very useful, I've saved it!


I'm glad to hear that you are considering tick born illnesses. I would get tested for them. It can help narrow down certain diagnosis either way. I had alot of your symptoms and found out I tested positive for Lyme ... Rocky Mountain Fever etc. It actually led to the discovery of an antibody I was born without. Alot of your symptoms are consistent with peripheral neuropathy. One that you didn't mention because you might not have realized what was going on is your hand popping open and dropping things. Good luck


Boydsfoolishrose - are you in the UK or US? Do you have any recommendations of somewhere to get tested? How are you now, what treatment did you have?

I haven't noticed the hand popping open thing, although my hands are quite weak at times (weren't before), and sometimes parts of them go numb/tingly and that's been for ages. Although i now think i've been ignoring a few things that were there and were odd but not massively intrusive until the heart probs made me go to the Dr.


I am in the US. Here you would have to go to a pain doctor or Neurologist and have nerve conduction studies done to treat the nerve damage. I have malabsorbtion syndrome. I do not absorb iron.. b12.. proteins ..and consistently test low for vitamin D resulting in rickets. My pernicious anemia was diagnosed but never treated which did all the nerve damage. I was born with IGA Def. I suggest you have your immune antibodies checked. IGA, IGG, IGM, IGE and IGD. For years the best doctors told me they could find nothing wrong. Finally after 61 years they found it. In fact a secondary doctor ordered it while I was in the hospital and my primary referred to it as a weird test to order even after it solved the riddle. Good luck


Gosh, you had to deal with all that for so long before you got answers :(

I've never heard of immune antibodies tests so I will look into them too, although I don't think my NHS Dr. is going to be any help there. Although he did hint that at our next meeting if nothing showed he could consider sending me to haemotologist..I don't know if that would be the correct referral in this situation but I suppose if he feels he can't do/suggest anything else then its worth a try!

If you are born with IGA Def. would I have had problems younger though? (I am 35 years old). How are you now, how do they treat you?


Hello again It was a hematologist that found my problem. With my age and so much damage being done I haven't been doing well. I've had 14 blood transfusions. I have A- blood which is the rarest. The IGA def will cause reactions to donated blood with the antibodies. Basically my body stops making blood. Don't let them take too long in agressessivly treating your PA because I am the worse case scenario. Fight for every shot of b12 you need. If you aren't absorbing iron tablets switch to liquid iron immediately. That is the best advice I can give you.


Goodness, that is so sad that you've suffered for so long to get to the answers. I hope now your haemotologist has it under control and you are supported?

i have just today got a test result back showing low Ferritin at 13 (range 13-150) so perhaps that is my answer? Could B12 deficiency still be a problem for me when the Active B12 showed 120 (with over 70 replete?) My serum was lowish but the Active was high?

Could low Ferritin cause all my symptoms or not?


The others in the group know more about that than I do. But if you have PA you have B12 issues. From what I've been learning yes the b12 could be causing your issues.


Your serum B12 would be considered low in other European countries and Japan and bearing in mind "deficiencies begin to appear in the cerebral spinal fluid below 550 pg/ml" , ( Could it Be B12?" By Sally Pacholok ) plus you have definite neurological symptoms, then you should be treated according to the UKNEQAS guidelines below, especially being a high risk group as a vegetarian and with a struggling thyroid.

Not to treat would be risking irreversible neurological damage as there is no gold standard test. :

“In the event of any discordance between clinical findings of B12 deficiency and a normal B12 laboratory result, then treatment should not be delayed. Clinical findings might include possible pernicious anaemia or neuropathy including subacute combined degeneration of the cord."

The above UK research document is supported by many research papers and has a useful summary if GP won't read full document, It also tells your GP that, once b12 treatment is started, the test results don't mean anything and blood levels are not reflective of how effective the treatment is - it is the clinical condition of the patient that matters.....


Polaris, thank you very much for these - I had seen references elsewhere here and on B12D site and had taken the NEQAS info and filled out the protocol symptom list and BCSH guidance, and BMJ details to my Dr's he would only glance at them. Said sometimes they don't even treat people below range, let alone at my figures and he wouldn't want to jump to start a 'lifelong' treatment when symptoms could be many things. So I asked what other things. He just kept saying lots of things, but that (in his opinion) my thyroid and other tests were fine and we will wait for the test results remaining (MMA and homocysteine -which were at my expense- I don't think he had even heard of them or Active B12 test and shrugged that he didn't know who NEQAS are and the Holter monitor) and meet again - obviously this will be another 2 weeks passing. I said was there anything else we hadn't looked at, he was elusive.

I asked about ferritin as that hadn't been checked, so he agreed to check it but didn't think it would cause neuropathic probs. I asked if any other iron tests should be done, he said no just ferritin (which he clearly wasn't going to volunteer although said they can be an early sign of anaemia). Is there any other tests I am missing that could be useful? (starting to feel like a pin cushion with all this to-ing an fro-ing!)

I am frustrated and am a bit lost now in direction as I had really hoped the Active B12 test would be conclusive.

I'be been to the dr's maybe twice in 6 or so years before so i'm hardly a hypochondriac, but they don't seem to understand that i want to get to the bottom of it, wouldn't they if it was them?!



A few extra thoughts...

People need good levels of iron and folate to utilise B12 fully. Have you had a full blood count (FBC) recently? There might be clues on that.

I always get paper copies of any blood tests. Experience taught me not to trust what I was told over the phone.

If iron (ferritin) is low then red blood cells will be smaller (microcytosis) and the MCV and MCH on the FBC will be lower. If B12 is low and/or folate is low then the red blood cells will be bigger (macrocytosis) and the MCV and MCH higher.

If you have both low iron and low B12 and/or folate then your red blood cells may appear "normal" size and the MCV and MCH may appear"normal" and doctors may miss that there is a problem.

I always emphasise any neuro symptoms I am suffering (lots in my case). Has your Gp checked their copy of the BNF (British national formulary). Relevant info is in Chapter 9 Section 1.2. It is possible to get your own copy of the BNF.

I googled the BCSH Cobalamin and Folate guidelines. A lengthy document but well worth reading. A recent BMJ article with useful summary.


Thank you - my FBC results are above and all are 'normal' although my MCV is 97.2 and I did read somewhere that the old range had the top of the range at 94 and its more recently been moved to around 100. I showed my Dr the BMJ stuff, NEQAS alert, B12D protocol, BCSH guidelines but he is not interested, only interested that I am within range. Said they often don't always treat people even below range as its a lifelong treatment to commit to and my symptoms could be lots of other things. (I asked what other things more than once and he wouldn't answer). I didn't feel I could push it any further since my Active B12 result came back as 120 and that sounds more accurate? Still waiting on MMA and homocysteine results.


So I called to find out my Homocysteine results (as St Thomas forgot to send them) but they haven't arrived. However, my Ferritin results were back (only had it tuesday!) and results said 'Low'. comments - 'see Dr. as planned'. I asked the number and apparently 13 (told range is 13-150). So we may have a starting point finally!

So can anyone help me as to what this means when my FBC looks quite normal, is it something to be treated itself or a sign of something else? Are there any associated tests or things I should ask for when I see him (on 24th Aug...feels like forever away!).

Thank you everyone :)

(frustrated no one had tested for this in the last 4 months and it only got tested at my request and insistence on Monday. Have seen 3 different Dr.s at the practice!)


"So can anyone help me as to what this means when my FBC looks quite normal"

It could be as I suggested in my post above that the effects of low iron and low "normal" B12 are cancelling each other out in the FBC eg low iron can make red blood cells small and the lowish B12 can makes them big so when the size of the red blood cells is averaged they appear normal.

Some people have a blood smear (aka blood film) but this is difficult to get on the NHS. This might show up small red blood cells (microcytosis) and large red blood cells (macrocytosis) in the same sample. It might also show hypersegmented neutrophils which can be a symptom of B12 deficiency/PA. It is possible to have this done privately.

Low iron may mean that the metabolism of folate and B12 is not as effective as it could be because you need good levels of all three.

I hope your doctor looks into what is causing your low iron. Low iron is not uncommon in vegetarians. Has your GP discussed diet with you?

I am looking into the possibility of MTHFR mutations, these are mutations in a genes that affect folate metabolism.


Thanks very much, I will ask for the blood smear and see what he says. Perhaps he'll be more amenable with the embarrassment that it's taken 3 months to find low ferritin...we shall see. My appt is not till 24th which feels an age away. I made it clear every time that I am a strict vegetarian (7 yrs) however I had been craving meat recently and pointed out one time I saw him that I thought I had felt better for eating it. He laughed at me and said it wasn't related! Now I know my low ferritin I have started eating meat again since. ( I am not sure I will tell him this though as I don't want him to fob me off without supplements and say the dietary changes will be enough).

Thanks for mentioning the MTHFR thing, I shall look that up, although my folate was in the higher end of the range

Thanks very much for all your help.


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