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Pernicious Anaemia Society
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Can B12 cause all this?

Hi all

Been on this page and hypothyroid ones so apologies to go on about my issues. I've moved surgeries and had my first Drs apt this morning. Showed him my two sets of Blue Horizons thyroid and B12 test results, and said to him that although my thyroid results show nothing obvious, I have a HUGE list of symptoms which point towards that. He wasn't convinced and suspected B12 deficiency was much more likely, and that I may have gut absorption problems, particularly given my high serum folate levels too. The fact I haven't eaten meat for 22 years set alarm bells ringing for him too and suggested I may have been deficient for some years hence my symptoms. He has now ordered another blood test to check for B12, and has suggested B12 shots might be a good starter, but wants to test my blood first. If it comes back ok and doesn't think B12 is the issue, he will refer to me to a CFS clinic rather than an endocrinologist which is what I'd prefer given my thyroid suspicions. Do my symptoms below correlate with B12 problems? Some such as low heart rate seem to be the opposite and point more towards hypothyroid. I'm so fed up with feeling crap that I would even go private if it meant a specialist looking more closely at my issues. Happy to see this through but not if it's obvious he's barking up the wrong tree (again). Any advice would be greatly appreciated. Thanks. Steve

May 2016

Vitamin B12 - 201 (Deficient <140 pmol/L

Insufficient 140 - 250

Consider reducing dose >725)

Serum Folate - 45.23 (10.4 - 42.4 nmol/L)

August 2016

Vitamin B12 - 397 (Deficient <140 pmol/L

Insufficient 140 - 250)

Serum Folate - 45.4 (10.4 - 42.4 nmol/L)


Excessive tiredness even with 8+ hours of sleep

Aching muscles particularly legs and lower back

Stiff muscles particularly bad after sitting

Restless legs

Twitching eyelid

Zero libido

Lack of concentration / mental sluggishness

/ memory problems

Difficulty understanding what people say (not hearing related)

Constant lingering colds

Dry skin

Gritty dry eyes

Difficult losing weight despite exercise and diet

Large intestine pain

(colonoscopy confirmed all clear)

Slow heart rate

under 50bpm

Low body temperature

under 35C in the mornings, especially cold hands and feet

Wanting to be solitary

/ depression

7 Replies

About 10 years ago I was severely hypothyroid. I just recently learned I am B12 deficient, and have thought many times about how similar I feel to when I was hypothryroid, especially when it comes to the fatigue and confusion. So, if your thyroid levels look good, B12 may be the issue. But, trust your gut! We know our bodies better than doctors do.

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Did you take any B12 supplements between May and now? Do you take folate supplements?

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I took B12 sublingual tablets and patches as advised by my dr. This would equate to the increase to b12, but not folate


You took sublinguals ánd patches and the B12 only went to 397? Hmmm guess you didn't notice much? Can't you ask the dr for injections?


Your folate levels are high. This can be a sign that you have a methylation problem - particularly if you haven't been taking supplements for folate. Basically your body has problems fully processing folate to the methylated forms used by cells so it doesn't use much of what is in the blood leaving levels continually high. This is usually the result of having a particular set of genetic variants. This also impacts on your ability to process B12 in your blood into methylated forms but to a lesser extent.

NHS don't do genetic testing but you can get a genetic profile done privately which would show if you do have one of the relevant sets of genetic variations.

If your GP says your next set of bloods don't show a B12 problem I'd be inclined to double check that it isn't being ruled out because there is no sign of macrocytosis as this isn't a defining characteristic of a B12 deficency - just one possible sign.

Personally I think trialling B12 might be a good move though if you do have a methylation problem then that won't necessarily get over the problem with not having enough folate available at the cell level so wouldn't necessarily be a conclusive course of action. You might want to talk to the GP about trying a methylated form of folate to see if that helps.

Not having eaten meat for a while is unlikely to explain the deficiency as there is plenty of B12 in dairy/eggs and fish and most breakfast cereals are fortified with B12 - much more likely to be an absorption problem - of which there are many.

B12 problems with thyroid problems are unfortunately quite common and there is nothing to say that there aren't two things going on at the same time.


Hi StevieP43.

I'm really sorry to hear that you're having such terrible problems with your health.

As sirmika says, there is a lot of cross-over between thyroid issues and B12 deficiency. The symptoms you describe could be either, neither, or both! It's often very difficult to sort out exactly what is going on.

What thyroid blood tests have you had? My knowledge of thyroid issues is fairly limited but I do understand that simply testing TSH is not sufficient to give a full picture. Do you have thyroid results that you could post here or in the HU thyroid community?

Your doctor is to be congratulated for considering B12 deficiency: many don't. And it could be that B12 deficiency is a problem as your levels do look a little low. This could be related to diet, taking PPI's or other drugs that deplete B12, absorption problems, pernicious anaemia, gastric or intestinal surgery, general anaesthetic or taking nitrous oxide etc.

If your GP is willing to trial B12 injections to see if this brings health improvements, this would be a very good idea. B12 cannot do you any harm and may do a great deal of good. Often, the only way to know is to give it a go.

Has your GP tested you for,pernicious anaemia (PA)?. Pernicious anaemia can be an autoimmune disease and people with autoimmune PA often have thyroid problems too (Hashimotos Thyroiditis is also an autoimmune disease). The two often go hand in hand.

So just having a little thought about specialists...thyroid problems are usually treated by an endocrinologist, who will do a full thyroid screen and also screen for other autoimmune diseases as well (not a bad idea since people with one autoimmune disease often have others as well - they're like busses, they all group together).

So...would be really interested to know why you would prefer to go to a Chronic Fatigue Specialist (who, presumably, will only be dealing with CFS, rather than investigating other possibilities). A thought - have you been diagnosed with CFS? People often post here saying that they have been misdiagnosed with CFS for many years, and the find they have PA or B12 deficiency (I am one of them ).

With respect to seeing a private consultant, one of the difficulties is identifying the right one! Many (most) have little knowledge of B12 deficiency (if that is the problem) and an added complication is that you would have to see several different consultants to sort out exactly what is going on (as they all have this own specialist areas).

For instance, people with B12 deficiency (again, if that is what thr problem is) can be referred to a neurologist, haematologist, gastrologist, endocrinologist...depending on the range of symptoms suffered (B12 is used by all systems and functions in the body and can cause multi-system symptoms). So, if you happen to need all of them, it'll get very expensive! And the factor in the potential thyroid issue...and so it goes 😀.

Your folate levels look high, but if I may, I'm going to leave other more knowledgable folk to comment on your blood results...

Finally, can I just say that I think your GP is in the right tree...many can't even manage to see the woods (most are very ill informed about B12 deficiency and, incidentally, thyroid issues too!).

If your GP offers a trial of B12 injections, I'd take it to see if it makes a difference. But just get him to do all your blood testing first, since supplementation with B12 can skew any results.

Good luck and would be interested to hear how you get on.

P.s. The pinned posts at the right hand side of the home page will give you lots of very useful i formation about B12 deficiency and PA.


Thanks all for your replies. I stopped supplementing everything for about 3 weeks before the Dr visit and blood test and frankly felt bloody awful. Due to get my results back on Monday. I asked the nurse when she was taking my blood what he's testing for and it's fairly standard - vits including B12 and D, kidneys, thyroid, and also glandular fever (although I said I've felt like this for 10 years so that's a bit pointless but he's doing it anyway!). These are the same as my previous doc tested so I know the results already - low B12, high folate, fairly low D. My B12 won't be low enough to warrant injections on the NHS, and I also doubt he will test for Pernicious Anemia as my previous Dr dismissed this completely. Can I insist on a course of injections to see if it helps? Can I insist on testing for PA? If not, how do I get these privately - do I need GP referral? I'm willing to pay. Feel like crap, although taking supplements such as B12 patches, D etc. at least allow me to function.

Just one other question - I have a really low heart rate (regularly under 50, sometimes low 40s), yet from what I've read PA should cause a fast heart rate. I don't get dizzy from it, but occasional shortness of breath (have to take deep breaths every once in while, as if I forgot to breathe). Also my body temperature is always well under 37c. Forgot to mention both to the Dr last time so will mention it next time.

Also in answer to other queries I'm not on any medication other than shop bought vit and mineral supplements

Thanks all for your advice.



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