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GP blood test for B12 - but should other tests be done too ?

Applethorpe profile image
25 Replies

I’ve recently been posting on the thyroid forum.

I have had frizzy feeling feet, then going up my legs, but it has calmed down a lot quite suddenly. The feet started overnight and would be fine in the day. The feet and legs together went away in the afternoon. I’m not sure this really sounds like a vitamin deficiency ?

I’ve had recent B12 results which appear fine

B12 514. ( 180 - 999 )

Active B12 73.5 (37.5 - 188.0)

Even so, given the symptoms, I asked my GP to check for PA. She will happily do B12 again. However, I had read that there are several blood tests needed to check for PA but she said no, ‘maybe privately’.

My specific question is, are the suite of tests listed supposed to be done by GPs or do only consultants do them in the NHS ?

I’ve not been told to refrain from using any supplements prior to testing. Should I ?

Thanks for your help

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Applethorpe
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GW1000 profile image
GW1000

Hi - a locum GP requested an Intrinsic Factor Antibody test for me but the lab declined to do it saying my B12 was too high (315 ng/L - I had supplemented but stopped about 3 weeks before. My initial B12 test was 210 ng/L). I was later referred to Neurology who after an MRI and a very long time tested IFAB, MMA and Homocysteine. I don’t think my GP would have been able to request them where I am.

It sounds like you have an interested GP… I would ask her if she would accept the results of tests done privately before you pay for anything. I had done a private Active B12 test which was below range - it wasn’t accepted by my GP. It did probably lead the way to the IFA request and neurology referral, but I’ve essentially had a years delay in treatment because they wouldn’t accept it. (Would have gone fully private a year ago if I had known it would take this long).

Are your fizzy/frizzy feet happening frequently? Not just a one off? It’s a good way of describing it! - I currently have fizzy hands but previously it was really just two fingers on one hand that felt odd. Also very tired, brain fog, word loss… I also have an underactive thyroid. The last of my loading doses is what has convinced me that the B12 is helping - but I now need to go back and ask for them to be continued…

Applethorpe profile image
Applethorpe in reply toGW1000

I started with a couple of dots of changed sensation in my fourth and fifth fingers on my left hand, about three months ago. A trapped nerve, I speculated ( hoping it would resolve ). That’s not got better or worse. It was a couple of weeks ago that my feet started getting frizzy in bed. I thought it might just be the cold. It was when it went up the outside of my leg, during the day, that I conceded defeat and rang the GP. But the following day the frizzy feeling had all but gone ! It’s been there, but mild, in the last few days.

I think my GP appreciated that I was trying to improve my own health. Their hands are so tied by what they are allowed to do, so in a way they might be grateful to be presented with some results.

I’ve had ME (CFS) for a long time and then I got de Quervain’s / subacute thyroiditis. Although my thyroid blood tests returned to normal, my symptoms have never gone away so I have been doing private tests to get to the bottom of it. Either way, I suffer from conditions that cause fatigue, poor concentration etc so I can’t say whether B12 issues may be contributing.

Oddly enough, my ME (CFS) consultant tried me on red injections of vit B12. That was 15 years ago. It was rather speculative and I didn’t notice any benefit.

GW1000 profile image
GW1000 in reply toApplethorpe

That’s intriguing - it’s the forth and fifth fingers of my left hand that affected me too. And pretty much unchanged for a long time - there have been many times I’ve thought I must be imagining it but then it’d get just a little bit worse but enough to convince me (for a while anyway!) that it was real. I had one isolated episode when pins and needles spread right up my arm - that’s when I was referred to neurology.

It’s only been the very last of my loading doses that has helped me believe it’s the right thing. Following it I had really hot hands for just less than a day and then really tingly hands the next day. Unmistakable as “things” happening. My mind has been sharper, mood better (one day of much, much better, now slipped back to just a bit better) and a bit less tired. I’m very conscious that this all only happened after my last injection. I think I’m very lucky that I’ve seen that change as if I hadn’t I’d have been thinking it didn’t work and it wasn’t a B12 problem after all. How long did you have B12 for before? I wonder if it just wasn’t for long enough?

I’m really sorry to hear you’ve got ME and de Quervain’s too - that’s a lot to deal with! Good luck with finding some answers. With my further tests my IFAB was negative, MMA well in range but Homocysteine just above range. The lack of a definitive test is unfortunate and I think quite confusing for Drs too.

Applethorpe profile image
Applethorpe in reply toGW1000

I’ve been hunting around for my old consultant’s letter but it was so long ago… I think I had weekly injections for a couple of months and then gave up as I saw no effect. I did find a later letter which said I should continue for another year. I’d forgotten that I was given some tiny tablets of folic acid to take at the same time.

I posted a link below to a study about B12 and ME. One of the factors which correlated with a good response was taking it for longer. Although maybe the patients who continued saw an early benefit, and so they carried on for longer with the treatment.

Also, it seemed to matter what type of B12 you were injected with. That’s why I was so keen to find the letter as I feel like I might have had the less effective one.

Of course the SWLondon Guidelines which are for my area explicitly tell doctors NOT to prescribe B12 injections for ME. That’s par for the course with ME treatments.

Dancer57 profile image
Dancer57

Hi

I did an active B12 private test and came out as below reference range:-

Active B12 28.6 (37.5 - 188)

I asked my GP for an MMA test as suggested by the company that tested and she said they don't do that. However, she did arrange a Complete Blood Count, total serum B12, vitamins and an Autoantibody test and Intrinsict Factor. That was all on the NHS.

I was shocked she did those for me but I do believe it depends on the GP and also which Trust you come under. They tend to vary, which is not helpful at all.

Interestingly, my total B12 was 444 (I don't take supplements). I tested negative for Intrinsic Factor Antibodies but positive for Parietal Cell antibodies.

I have slight loss of skin sensation on leg, mild fatigue, tinnitus, digestive issues and occasional bouts of vertigo. I also have Autoimmune Thyroiditis.

I am going to arrange a private MMA test, might do the urine one, yet to decide. Whether the GP will accept results not sure. To me that would be ridiculous as they are not offering the test on the NHS. None of us want to wait until we get quite ill!!

I am not an expert but I believe you shouldn't take any B12 supplements for a few weeks before any test, but I am not 100% certain on that.

It is not easy getting tested or treated so I do sympathise. Good luck.

Applethorpe profile image
Applethorpe in reply toDancer57

I’ve been on omeprazole for recent gastritis. Autoimmune thyroiditis… mm, definitely crossover there.

The NHS does seem determined not to test you, so you don’t get diagnosed with anything, so they don’t have to treat you. But we insist on trying to DIY !

Noelnoel profile image
Noelnoel in reply toApplethorpe

Sorry to interrupt but lots of us on the thyroid forum have wrongly been prescribed omeprazole for gastritis and digestive problems

Many GPs reach straight for their prescription pad and offer PPIs instead of investigating the cause. If they bothered to do so they’d find that in a very significant number of cases, the problem is low acid not high. Admittedly, many of the symptoms are the same but it’s a grave mistake to get the two confused

My apologies if I’ve meddled but I wanted to point this out in case you were unaware that this unfortunately happens far too freqently. Hypothyroidism and low acid often come hand in hand, causing significant deficiencies in

B12

Folate

D3

Ferritin

And others

Low stomach acid causes poor absorption of the nutrients in our food. This then leads us down the supplement route. If we take PPIs that lower stomach even further then we’re in trouble because in those conditions we’ll never be able to absorb nutrients properly from our food OR supplements and that’s why some end up on B12 injections

Again, apologies if you know all this …

Applethorpe profile image
Applethorpe in reply toNoelnoel

No , I appreciate your reply 😀

I’ve been reading as much as I can about thyroid, and I am glad to say that your neat summary is familiar by now. ( So some of it’s actually gone in ! )

My ‘gastritis’ symptoms were vomiting so severe that I had to go to Urgent Care. They gave me the O-zole and I was a lot better within 3 days. I stayed on it for a few weeks and then stopped. Within three weeks I was vomiting again ( last weekend ) and immediately initiated the O-zole again and again that seemed to sort it.

Of course, if I have gastritis I’d like to know if there’s an underlying cause - and the same goes for low stomach acid. If you look at my last post on the thyroid forum I mention the gastritis and you are welcome to pile in there.

QUE6T-33 profile image
QUE6T-33 in reply toDancer57

Hi, I supplement with B12 (not injections). I’m due take an Active B12 blood test & need to stop taking supplements for a period of time before test. I’ve been told 2 weeks, a month and another Lab said just keep taking supplement. For those of us taking supplements, is there any guidance on time lapse ? Appreciate this is possibly different for those injecting. Thanks

Applethorpe profile image
Applethorpe in reply toQUE6T-33

I hate it when that happens ! As a patient, I’m happy to follow instructions, but when you get conflicting advice…..

I can’t help with an answer. I’m getting the impression there isn’t one.

Dancer57 profile image
Dancer57

Sorry forgot to mention. Do you have any family history of PA? My mum had it so it is worth mentioning it to the GP if you do as it can run in familities.

Applethorpe profile image
Applethorpe in reply toDancer57

no family history for me, thankfully

Dancer57 profile image
Dancer57

It is difficult if you have more than one health issue going on. Other autoimmune conditions do have similar symptoms!! Regrettably the NHS due to limited funds do basic testing on some stuff which doesn't always help when you looking for a diagnosis.

Anyway, I wish you well.

Sleepybunny profile image
Sleepybunny

Hi,

Welcome to the forum.

"are the suite of tests listed supposed to be done by GPs or do only consultants do them in the NHS "

I think a GP should be able to order tests such as serum B12, full blood count (FBC) and IFA (Intrinsic Factor Antibody) test. I suspect that for other tests such as homocysteine, MMA and Active B12 (holotranscobalamin) you will probably need to see a specialist.

It's possible to get all these tests privately in UK but can be very expensive.

Sometimes NHS doctors will not accept results of private blood tests but a significant result in a private test should be enough to nudge them to order the same tests or refer you to a NHS specialist who can order them.

Supplementing with B12 prior to having the blood tests may affect the results.

Testing for PA

pernicious-anaemia-society....

Thread about tests for PA and B12 deficiency

healthunlocked.com/pasoc/po...

It's possible to have B12 deficiency symptoms with a normal range serum B12 result.

You may want to look into Functional B12 deficiency. This is where there is plenty of B12 in the blood but it's not getting to where it's needed in the cells so the person develops deficiency symptoms.

MMA, Homocysteine and Active B12 (holotranscobalamin) tests may help to diagnose functional B12 deficiency.

Blog post about being symptomatic for B12 deficiency with normal range serum b12.

b12info.com/your-serum-b12-...

What to do next if B12 deficiency is suspected

b12info.com/what-to-do-next/

If you suspect PA (Pernicious Anaemia) is a possibility then worth joining and talking to PAS (Pernicious Anaemia Society).

pernicious-anaemia-society....

PAS membership is separate to membership of this forum. It is open to people worldwide and you do not need a PA diagnosis to join.

pernicious-anaemia-society....

UK doctors can sometimes be reluctant to treat someone who is symptomatic for B12 deficiency but has a normal range serum B12 result.

NICE CKS (Clinical Knowledge Summary) for B12 deficiency and Folate deficiency states

"Note: clinical features of vitamin B12 deficiency can occur without anaemia and without low serum levels of vitamin B12.

cks.nice.org.uk/topics/anae...

Unhappy with treatment?

How to write letters to GPs about B12 deficiency

b12info.com/writing-to-your...

Thread about Patient Safety, has useful links for those in UK having difficult health experiences with B12 deficiency

healthunlocked.com/pasoc/po...

I left more detailed replies on the thread "Recently diagnosed with pernicious anaemia" about 4 days ago which has some B12 info that might be useful to you.

healthunlocked.com/pasoc/po...

There's also a pinned post "Various PA/B12D" resources with lots of B12 info. Pinned posts are on right hand side of screen if on computer. You may need to scroll up or down to find them.

I'm not medically trained.

Sleepybunny profile image
Sleepybunny in reply toSleepybunny

"I’ve had ME (CFS) for a long time"

Many of us here have a ME/CFS/fibromyalgia diagnosis in our medical history.

Misdiagnosis of B12 deficiency as other health conditions

b12info.com/misdiagnosis/

Applethorpe profile image
Applethorpe in reply toSleepybunny

Hello 😀

Thanks very much for the info.

I’m not ‘medically trained’ either but I’m getting there, lol !

I feel like I might end up with another ‘normal’ B12 result. I suspect the GP would do the IF antibodies - but only after a deficient B12 result. ( ie ‘not warranted’ otherwise )

I suppose it’s the gastritis connection which makes me think it might be B12, along with my (undiagnosed ) thyroid problems.

I’m confident that I have postviral ME. Following the link in your below post brought me to an extremely interesting paper about treating ME with B12 and folic acid, which my consultant tried without success. However I might just have needed more doses.

journals.plos.org/plosone/a...

Sleepybunny profile image
Sleepybunny in reply toApplethorpe

"I suspect the GP would do the IF antibodies - but only after a deficient B12 result. ( ie ‘not warranted’ otherwise )"

A negative result in IFA test does not rule out PA.

Diagnostic flowchart from BSH Cobalamin and Folate Guidelines (UK document) which mentions Antibody Negative PA.

stichtingb12tekort.nl/engli...

NICE CKS B12 deficiency and Folate deficiency Section Background Info - Causes states

"Antibodies to IF are very specific for pernicious anaemia, however, they are present in only 50% to 70% of people with the condition."

cks.nice.org.uk/topics/anae...

One thing I urge UK forum members to do is to track down the B12 deficiency guidelines used by their ICB (Integrated Care Board) or Health Board and compare them with NICE CKS link.

If you can't find them by searching online or by searching forum threads here, best bet is to submit a FOI (freedom of Information) request to ICB/Health Board asking which B12 deficiency guidelines they use and for a link to or copy of them.

Some of these local B12 deficiency guidelines are not helpful. See blog post below.

b12info.com/gloucestershire...

"I’ve had recent B12 results which appear fine

B12 514. ( 180 - 999 )

Active B12 73.5 (37.5 - 188.0)"

Just wondered if you had older serum b12 results to compare these results to.

Wrong ideas about B12 deficiency

Many of us here have met health professionals with poor understanding of PA and B12 deficiency.

Misconceptions about a B12 deficiency

(From Dutch B12 website - units, ref ranges, treatment patterns may vary from UK)

stichtingb12tekort.nl/engli...

Diagnosis and Treatment Pitfalls

(From B12 Institute in Netherlands - units, ref ranges, treatment patterns may vary from UK)

b12-institute.nl/en/diagnos...

B12 article from Mayo Clinic in US

Aimed at researchers and health professionals

The Many Faces of Cobalamin (Vitamin B12) Deficiency

ncbi.nlm.nih.gov/pmc/articl...

Table 1 in above article is about frequent misconceptions about B12 deficiency that health professionals may have.

"I suppose it’s the gastritis connection"

Have you accessed your medical records and read what was said about gastritis when diagnosed?

AMAG (Autoimmune Metaplastic Atrophic Gastritis) is a type of gastritis that is associated with PA.

Applethorpe profile image
Applethorpe in reply toSleepybunny

Historic serum B12 results

2012. 411. ( 211-911) (pre thyroid problems)

2014. 419. (No range given ) (soon after thyrotoxicity)

Latest 514 (180-999) (June this year - before gastritis and neuropathy)

They look quite consistent.

The new serum B12 will be back in a couple of weeks, so it will be interesting to compare.

My H Pylorii test ought to be back this week too. If negative, I’ll certainly ask the GP why they think I have developed gastritis.

Mixteca profile image
Mixteca

Best not to supplement before testing. I had the parietal cell antibody and intrinsic factor tested through my GP but the others were refused as not offered in my area. You can still be B12 deficient with your serum level - the active test paints a clearer picture.

Applethorpe profile image
Applethorpe in reply toMixteca

Hi there,

I happened to do an active B12 fingerprick along with other thyroid related vitamins.

Active B12 73.5 (37.5 - 188.0)

It’s within the stated range, which gave me some reassurance, but I’ve learned to take a ‘normal’ range with a pinch of salt. Not sure if 73 is considered high enough ?

Mixteca profile image
Mixteca in reply toApplethorpe

Is that measured in pmol/L? All info is important when trying to judge.

Applethorpe profile image
Applethorpe in reply toMixteca

Yes that’s right. A bit lazy to miss off the units, I admit !

Mixteca profile image
Mixteca in reply toApplethorpe

I think your levels could be showing an indeterminate status, possibly a subtle deficiency? I found NICE guidelines that go into some detail about active B12 vs serum assays and the likelihood of deficiency. Hope that helps.

nice.org.uk/guidance/GID-NG...

From a PA website so patient orientated:

perniciousanemia.org/b12/de...

Applethorpe profile image
Applethorpe in reply toMixteca

Both those links were really useful - thanks.

The NICE guidelines seems to suggest that 70pmol/L is the dividing line between possibly deficient and fine ( with less than 25 being definitely deficient for me as a non pregnant woman ) so mine of 73 looks decidedly borderline.

However, the GP is doing serum B12 which, if it comes back at a similar level to my previous tests, will probably rule out deficiency in her mind. The NICE guidelines seem to say that even if one test is low, if the other is fine, then you aren’t deficient.

The link about the benefits of the ACTIVE B12 test was extremely interesting and certainly convinced me that the serum, in comparison, is not much use.

Mixteca profile image
Mixteca in reply toApplethorpe

You're most welcome. Serum is an indicator but combines active & inactive B12, which is the problem, giving no clue as to what's happening at a cellular level.

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