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B12 Query Directed to you by Thryoid Healthunlocked

My last 2 private blood tests are below.

12 Apr Horizon and 10 July Medichecks

CRP 3.00 2.7 (0-5.00)

Ferritin 89.3 (13.150) 102.3 (20-503)

TSH 3.97 2.92 (0.27-4.2) had increased from 25 to 37.5 levothryoxine per day

T4 Total 100 (64.5-142) 91.7 (59-154)

Free T4 15.07 15.18 (12.22)

Free T3 3.88 3.92 (3.1-6.8)

ATPeroxidate Abs 148.4 (<34) 145.5 (0.34)

Anti Thryroglobulin Abs 29 (<115) 223.6 (0-115)

Vitamin D 55 deficient<25, insufficient 25-50, reduce dose>175, 80.17

deficient <25, insufficient 25-49, Normal 50-200, reduce dose >200

Vitamin B12 392 deficient<140, Insufficient 140-250, reduce dose 725, 268 (140-724)

Serum Folate 28.49 (8.83-60.8) 10.13 (2.91-50)

Should I be concerned about the B12 results. I am 62 year old woman. Have had issues with tingling and heavy left leg and arm pretty much all my life. Had tests, brain scans, but not within the last 20 years. I was diagnosed with hypothyroidism/Hashimotos 3-4 years ago. I am having trouble with my legs feeling weak and extemely painful. I cannot walk for more than half a mile without problems, sometimes feel my legs are going to buckle underneath me. Saw GP yesterday gave him last 2 results, said B12 fine. For over 20 years I have been taking Omeprazole, 20mg at first, I requested to drop down to 10mg about 2 years ago, now I don't take it very often and rely on rennie or gaviscon when I need it for heartburn/axcid reflux. I have quite a few of the symptons listed, including tinnitus, clumsiness, sleep disturbance, burning shins, brittle flaky nails (all of which I believe can be Hypo symptoms). I have a cousin with PA and my sister's daughter has Myasthenia Gravis. Should I push for further NHS blood tests.

5 Replies

Hi Wilsospw. Hmm, this is not an easy question to answer because as you recognise, there are a lot of cross-over symtpoms between B12 deficency and hypothyroidism/Hashimoto's...and other things too.

Can't really comment on the thyroid results - the thyroid folks are much better at that so assume you've posted your thyroid results there.

It's difficult to assess any changes to ferritin and folate levels between April and July because two different reference ranges are used. Having said that, both are within the reference ranges and look okay.

At 392 the serum B12 level is within the reference range but...the serum B12 test is a blunt instrument for assessing whether B12 deficency is present or not. For most people this might be okay, but it is possible to have an apparently 'normal' B12 level and still have B12 deficiency. So...the test result should not be used as a sole marker to determine B12 deficiency. It's important to look at symtpoms...and if symtpoms of B12 deficiency are present, then these should take precedent over serum B12 levels.

And that's why its may be difficult to sort out...because your symptoms (as you recognise) could be due (or partly due) to your thyroid issues. If your thyroid is well controlled...or even if it's not.... its worth investigating the possibility of B12 deficiency. (Note that you have previously taken Omeprazole for many years - this can impeded the absorption of vitamin B12).

Note: if you have previously taken any B12 supplements, mention this to your GP because it may have skewed the serum B12 results.

An MMA and homocysteine blood test may help to clarify the position (these will be raised if you have a B12 deficiency - though they can be raised by other things too). MMA is the better one to try and get done. Some GP's have not heard of this but if your GP rings the lab at your nearest large hospital, they may be able to advise if they do it. Some hospitals don't offer it at all (unfortunately) though it is available privately (bit costly though).

You have autoimmune conditions in the family and you also have an autoimmune condition so...on that basis, you should ask your GP to test you for PA (anti-IF antibody test). This test is not too reliable - it produces 40% - 60% false negative results. So you could test negative and still have PA.

And another thought...autoimmune conditions in your family and you have one too. Autoimmune diseases tend to arrive in clusters so just wondering if your GP has done an antibody screen to see if you have another underlying (undiagnosed) autoimmune condition. An antibody screen won't diagnose specific condition but if any of the results are raised, then further investigations should be undertaken (via referral to a rheumatologist). Certainly worth doing considering your long-standing and current symptoms. For peace of mind, if nothing else 😀.

So the answer to,your last question about asking for more blood tests - yes. MMA, homocysteine, anti-IF antibodies and full anti-autobody screen.

Going to leave you some links that might be helpful...quite a lot of links but most are only one page long...sorry, haven't the time to sift through them so pick what's most appropriate for you (links annotated soyou'll be able to spot what they're about quite easily).

Sorry the aren't any easy answers 😖

Good luck and post again if you have any more questions or need more help.

Here's the links...

b12researchgroup.wordpress.... (Serious Caution Note about the use of Oral and Sublingual B12 Supplements)

evidence.nhs.uk/formulary/b... (BNF B12 Deficiency: Hydroxocobalamin Treatment Regimes)

pernicious-anaemia-society.... (PAS Symptom Checklist)

stichtingb12tekort.nl/weten... (BSH B12 Deficiency / PA Diagnostic Flowchart)

onlinelibrary.wiley.com/doi... (British Committee for Standards in Haematology (BCSH) Guidelines: Treatment of B12 Deficiency and Folate Disorders)

bloodjournal.org/content/bl... (Haematologist B12 Treatment Review March 2017 – Includes Advice No Reason to Advise Against Self-Injection/More Frequent B12 Injections)

cks.nice.org.uk/anaemia-b12... (NICE Guidelines Treatment of B12 / Folate Deficiencies)

onlinelibrary.wiley.com/doi... (UKNEQAS B12 Treatment Alert, Neurological Symptoms and Risk of Subacute Combined Degeneration of the Spinal Cord – Immediate Treatment with B12 Injections)

stichtingb12tekort.nl/weten... (Problems with Serum B12 Test)

stichtingb12tekort.nl/weten... (Testing B12 During Treatment)

stichtingb12tekort.nl/weten... (Misconceptions About B12 Deficiency – Good to Know Before Seeing GP)

stichtingb12tekort.nl/weten... (B12 Treatment Safety / Long Term Treatment for neurological symptoms)

stichtingb12tekort.nl/weten... (B12 Deficiency: Neurological Symptoms Can Present Even When B12 is ‘In-Range’ and Without Macrocytosis (large red blood cells) or confirmed PA Diagnosis)

stichtingb12tekort.nl/weten... (B12 Deficiency and Intrinsic Factor – Can Be Negative and Still Have PA)

stichtingb12tekort.nl/weten... (B12 Deficiency and Neuropsychiatric Symptoms)

Oh oop...links with information about MMA and homocysteine blood tests missing...will post this reply, dodge off and collect them, and then edit to add them in.


stichtingb12tekort.nl/weten... (Methylmalonic Acid – MMA)

cdc.gov/nchs/data/nhanes/nh... (Homocysteine and Testing Information)


1 like

Thank you. My b12 for this week was 268. Sorry not very clear there were two results. Apr and this week I will look at the links.


Ah ha...my bad...missed the second result. So...it's falling...certainly should investigate further.

Also - don't take any B12 supplements - will affect the tests and you'll struggle to get a proper diagnosis/treatment.

Good luck 👍

1 like

It is well known on Thyroid UK forum that many people eventually succumb to many other problems when thyroid treatment is inadequate (only feel well when their thyroid is suppressed), or cannot convert T4 to T3. If you haven't already read it, 'Understanding Thyroid Disorders', written by Dr A. Toft, published in association with the BMA, gives good advice and I showed this to my GP to avoid having my dose of Thyroxine reduced, but eventually chose to buy my own NDT:

"Typical results would be a fT of 24 pmol/l or TT4 of 140 nmol/l, and a TSH of 0.2 mU/l. In some patients, a sense of well being is achieved only when fT4 or TT4 is raised, for example 30 pmol/l or 170 nmol/1 and TSH low or undetectable. In this circumstance, it is essential that the T3 level in the blood is unequivocally normal in order to avoid hyperthyroidism."

I expect you know that many researchers believe leaky gut/intestinal disease is the source of autoimmune disease and I believe this is at the bottom of all our own family autoimmune/Hashimoto's thyroid/B12def. problems.

This research posted by 'Diogenes', scientist and advisor on TUK forum, shows the progression from Hashimoto's to gastric atrophy, followed by damage to parietal cells, leading to reduced or absent acid production, followed by PA.



Re. your serum B12 level, many experts believe the serum B12 levels are set too low, especially for older people, who are more likely to be deficient in hydrochloric acid - essential for absorption of B12:

'The traditional cut-off values for deficiency are too low and deficiency is more common than generally thought,’ explains Professor David Smith. ‘We have evidence that people suffer harm from levels up to 300pmol/L, yet they receive lab reports saying their levels are normal. That’s why it’s important to ask for your exact level if you’ve been tested.’

The signs of deficiency — which typically include tiredness, muscle weakness, disturbed vision and numbness or tingling — are insidious and slow to develop, he says, so ‘people often think they are just getting old’.

‘Or they may go to the GP and they sometimes are misdiagnosed with depression. This condition isn’t obvious like a heart attack or a stroke, it builds up slowly.’ But early treatment can make a big difference, says Professor Smith. ‘Memory loss is one of the key signs of advanced deficiency. If they are caught early enough, the neurological signs can improve after treatment.'

BMJ research document with useful summary if GP won't read the whole document:


Good luck with your appointment Wilsospw

Ps Might be a good idea to take someone close with you for extra support, as GP less likely to dismiss symptoms, etc. with a witness present.


Thank you. I will go back to gp.


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