B12 deficient but could I have underactive thyr... - Thyroid UK

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B12 deficient but could I have underactive thyroid too?


Last March I went to the GP with muscle pain in hands, neck and back. Initially told I had sciatica. Took the naproxen but still didn't improve. Returned to GP who did a blood test and my B12 returned at 87, which is very low. I had been having symptoms of B12 deficiency such as fatigue, brain fog etc. but didn't really think it was any more than being an overworked teacher. Whilst I was being treated with B12 injections I was also sent for a nerve test on my hands and diagnosed with early stage carpal tunnel. Despite having loading doses and 2 twelve weekly top ups of B12 my symptoms have not allieviated. I returned to GP as the pain in my hands and now legs and feet is unbearable at times and the GP gave me a steroid injection in my left wrist but still nothing has changed.

My fatigue seems almost normal now; asleep by 8 most evenings and an afternoon nap at weekends. More recently I have felt my throat feel tight and notice everything I eat and drink. I also weighed myself and realised I have put on over 2 stone since Easter but I've always struggled with my weight.

Is there a link between underactive thyroid and B12 deficiency? Should I ask my GP to test my thyroid function? I'm so tired and all it seems is that I'm constantly complaining and 'ill'.

14 Replies

Paffette71 Yes, definitely ask for thyroid function tests, see if they will do TSH, FT4, FT3 and antibodies.

Also ask for Vit D (low Vit D can cause muscle and joint aches and pains), Ferritin (low ferritin can cause fatigue) and Folate (B12 and folate work together).

I don't feel like I'm being forceful enough with the GP. I want to feel better but I worry I sound like a hypochondriac. I think even my husband thinks I'm just whining

SeasideSusieAdministrator in reply to Paffette71

If you want to feel better then you're going to have to stop worrying about sounding like a hypochondriac and ask for the tests to be done. You should be able to discuss your health concerns with your GP and not worry about it.

You can always get them done privately with a fingerprick test to do at home if you'd rather, then if anything shows up take the results and show them to your GP. If he doesn't like the fact that you've had them done and won't accept them then ask him to do them himself.

This is the best test as it does all the thyroid tests plus all the important vitamins and minerals


You can post your results here and members will advise.

shawsAdministrator in reply to Paffette71

Don't worry. Better to whine than be undiagnosed particularly if no-one has yet taken a blood test to check your thyroid hormones or suggested it.

I wont bore you with my run-around and many on the forum have also had similar. Many doctors don't give a blood test for thyroid hormones but will prescribe for symptoms (which may be hypo but they don't know them).

I think you may know the procedure if you are having a blood test to check your thyroid hormones?

shawsAdministrator in reply to Paffette71

Please don't worry about asking people who should be willing to do the tests.

As for me, I had no idea about a thyroid gland deficiency and also 'where was the thyroid gland'. It became very clear to me when eventually diagnosed about six or seven years later that none of the doctors, consultants, barium swallow etc etc hadn't a clue either

I had a barium swallow and told I had a post-cricoid web in my throat which I could choke if it wasn't removed. Underwent anaesthetic only to be told I didn't have a 'web'. What was it then I asked. No answer was the response.

Another Consultant said I had high acid - I wrote later saying I had been diagosed as hypo. Both of the above were paid but no refunds were forthcoming.

I then went again to my GP and said there is something far wrong with me and I want to pay for a Full Body Scan. He reassured me and said he'd do a full blood test. Phoned me about 5 days later and said 'all is fine' all tests are good.

I was in and our of the A&E with palpitations. The final time I had to get assistance at the airport and was taken straight to A&E and kept in overnight and discharged with probably viral with high cholesterol (should have been a red flag with high cholesterol).

Later a first aider suggested my thyroid gland as he could see it was swollen. I phoned surgery and demanded a blood test form to be left for me. I was away from home at the time. Got the blood test done at 9 a.m. and by 10.30 another GP phoned and said come and get a prescription you have hypothyroidism. My TSH was 100. She also asked who requested the blood test form and I said 'me' myself.

Changed surgery after that. So get whatever you deserve to exclude everything and anything.

I said I wouldn't bore you but then thought I'd let you know :)

Try going to pernicious anaemia board- many people struggle with 3 monthly injections- 2 monthly are the guideline for neurological symptoms. B12 def and thyroid problems are fairly common together though. Have you been tested?

Not for thyroid issues but looking through forums and health advice websites I realised how similar the symptoms are. I just feel worn out by feeling worn out. Would love to feel 'normal ' again and pain free

I have a physio appt. for my nerve pain in Thursday and will then return to GP. I need to be more forceful and write everything down so that I don't miss anything.

Marz in reply to Paffette71

Not sure what the Physio can do - except treat the effects of your LOW B12 and possible low thyroid .... You really need to find the ROOT cause. Sorry - not being negative - just experience chatting out of turn :-)

Yes Paffette71 make a list have it in your hand and be determined to read it get answers or agreements that you want. I focus on telling myself GP is supposed to be helping me to be well it's what he trained for and wants to do?? I very stropingly Saud to mind you haven't tested ferritine etc he reluctantly Saud if it will put your mind at.rest I wilL result it was raised now he is listening to me more and discussing tests in future. I think nobody had questioned him before but because I had posted on here got brilliant advice read loads I had the confidence to do it! I did also take hubby (much to his reluctance he thinks Dr are never wrong) but I needed him to say he'd felt my Thyroid hotter than my throat for the previous 2 days,Dr did check with him I just sat there smiling (snuggly) it's very hard to be strong to Dr but try your best. Good luck big hug for courage

You might look into taking pyridoxal-5-phosphate (B6) for the nerve pain - you could be deficient in that, too. N-acetyl-cysteine might be something to try, too. And mitochondrial support, like phosphatidyl choline, carnitine, magnesium, d-ribose, and CoQ10.

And with a B12 level that low, you should be taking oral, ideally sublingual, daily, and considering injections 1-2 times a week.

If you look in Thyroid UK site there is a list of possible thyroid symptoms, around 300!

You may be surprised at many of them but that's one of the problems. Some GP's have no idea about this and instead treat you forcseveral 'different' problems when actually many are symptoms for just one thing-badly treated thyroid gland!

B12 Deficiency is a NEUROLOGICAL condition and NOT a Vitamin Deficiency. You should have had the injections every other day until the neurological pain and any other symptoms had abated. This practice is laid down in the Treatment Guidelines of Folate and B12 Deficiency .....


Any result under 500 can present with neurological symptoms - please look at the link below to view the neurological signs and symptoms - they come first :-)


Also click onto the heading Films and watch the videos to understand just how serious B12D is. You also need to know WHY ? Do you have Pernicious Anaemia ? Do you have gut issues ? Both are reasons for such low B12. Are you a vegetarian.

Just because GP's have little or no understanding of B12D does not mean your concerns point to you being a Hypochondriac - it is time for you to educate them. There are other tests that should be done to confirm B12D - like Homocysteine and MMA. Docs are of the mistaken belief that B12D does not exist in the absence of anaemia.

I would suggest buying the book - Could it Be B12 ? - by Sally Pacholock. You will be amazed. A trailer of a recent film about her work is on the the above link.

And yes you need thorough testing for the Thyroid as others have suggested. I have Hashimotos and a B12 issue due to medical oversights. I was always told that a B12 level of around the 300 mark was OK - NOT. I have spinal issues and neuropathy after 43 years without a Terminal Ileum - and only started B12 injections 3 years ago at 67.

Please think of yourself and do not leave things too late. I only began investigating my health on retirement in 2004 - you can click onto my name above and read about the journey. Until then I was just too busy getting buy in the only way I knew ...... it will only take a couple of minutes :-)

Wishing you well on your journey - keep on posting and asking questions too ....

Carpal Tunnel Syndrome is also a condition related to hypothyroidism. You don't say you have had your thyroid checked, so I guess this is your next option, see if they will test you for antibodies too. Even if your TSH is "normal", you may still have Hashimoto's disease if these are raised.

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