Pernicious Anaemia Society
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b12 deficiency and thyroid cancer?

After a second biopsy on my thyroid nodules, my consultant, who is checking them for cancer,left a message on my answerphone last night saying he needs to speak with me. I phoned his secretary first thing this morning but he's in surgery all day so I've been told he will probably phone tonight or in the morning. My follow up appointment for results was for August, so the fact he is contacting me earlier has me a bit worried. After the first biopsy I just got the results at the follow-up appointment.

I am still in early loading doses of b12 by injection but need to know, please.......if my fears are confirmed and it's thyroid cancer or the consultant wants to remove part or all of the thyroid, is it possible that could be avoided if b12 is corrected over time or does that have no bearing on thyroid cancer?

I would just like to be prepared for any discussion when I do get that call from the consultant. I don't really want to lose an important gland unless it's absolutely necessary.

Any advice most welcome.

Thank you.

11 Replies

Sorry that you think that you might have thyroid cancer.

I'm afraid that waiting for B12 levels to get better is probably just going to make things worse - acting as soon as possible is likely to be much more effective.

Research generally shows that people receiving B12 have higher rates of cancer and tend to develop bigger tumours than the rest of the population. No causal link to cancer has ever been established, though it seems likely that the reason for higher rates of cancer is probably the period when they were B12 deficiency meaning that a latent cancer had developed. When B12 supplementation starts it doesn't just help with healthy cell reproduction it also enables the cancer cells to reproduce slightly faster - leading to larger tumours.

I have heard of people with end-stage cancer using B12 infusions as a form of treatment - as it should help support healthy cells more than the cancerous cells - and it does seem to have worked for some but that is very much something that happens when all other options have been explored.

If you need to have an operation then it is important that nitrous oxide isn't used as an anaesthetic - or if it is that you receive aggressive B12 treatment after the surgery as nitrous oxide makes B12 in your body inactive so there won't be any B12 at the cell level.

Having said all that - there are probably a whole range of things that your consultant may want to talk to you about and cancer is just the worse case - it may be that there was just some problem with the biopsy and it needs to be done again ... really hope that it doesn't turn out to be cancer.

Its possible that the consultant might want to discuss delaying the B12 treatment but to be honest I think it would be better to opt for early treatment. B12 treatment can interfere with some anti-cancer treatments so the situation could get very complicated.

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Oh dear. No idea b12 could make things worse. I've literally jut got my latest results in my hand which look good, with all negatives bar one. Wondering now if this totally rules out b12 deficiency and it's one of my autoimmune conditions just causing peripheral neuropathy and I just have to live with with these pins and needles/burning sensations in my legs.

If it's okay, I will post my results here to see what folks think.


Hm. Can't seem to include a photo of results. Never mind.


You will need to start another post if you want to put photo up - make sure that you don't leave anything in the photo that will identify you as an individual,

The B12 hasn't made things worse but it could make things more complicated. Besides, you really don't know yet that it is cancer - that is still speculation.

B12 deficiency would kill you just as sure as an untreated cancer and it wouldn't be a pleasant way to go. Just need to take things one step at a time. You may be experiencing some of the psychiatric effects of B12 deficiency - eg lower tolerance to stress/higher levels of anxiety ... and possible that the B12 treatment could sort that out and leave you better able to cope with anything else that happens to come along.


I've now spoken briefly with the consultant. He says the recent biopsy shows the cells have now changed in the nodules and I have to make a decision about if I want him to operate or not.

He says the op is not without risk but he will be sending more details by letter.

When I told him there have been other health issues develop since I saw him in January, including neurological problems with my legs,he said that changes things and HE may make the decision, once we meet and I enlighten him of developments.(I forgot to mention I'm having b12 injections but I will make a list to tell him when we meet).

I also got results this afternoon of a saliva adrenal stress test that has come back out of range.

It's all a bit confusing but at least I have a few answers and some things to mull over.


good that the consultant took note of the other health issues. Hope the meeting is useful. As ever - read what you can and ask questions ... and really good to go armed with a list of points.

Sorry that you are having so many problems at the moment. Unfortunately having one autoimmune problem often goes hand in hand with having a whole string of other conditions.


Good luck and very best wishes: thinking of you and hoping they can make you feel better again soon. x

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Thank you. Apparently the biopsy result is known as a Thy 3.


Chocoholic, Thy3 is indeterminate. If it's not possible to wait and have a repeat FNA in 3 months you will be offered a hemilobectomy (partial thyroidectomy) to remove the nodule and lobe. Histopathology on the larger sample will confirm whether the removed nodule is malignant or benign.

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Thank you, Clutter. Funnily enough I found that very link myself late last night and it is a very helpful one.

I think I will search this site to see what others decided about 'to op or not to op'. It's a hard decision but as I'm feeling so under the weather generally, I think I'd rather wait until I feel a bit stronger physically, before opting for any operation.

'Increased risk' is just that not confirmed cancer, so for me, maybe a wait and see approach might be preferable for now.


Chocoholic, I had Thy3 but FNA wasn't repeated because hemilobectomy was done to remove the nodule which was compressing my trachea. Histopathology was malignant but because follicular thyroid cancers are slow growing the tumour hadn't grown much in the 5 months since the lump appeared. Risk factors were high so I had completion thyroidectomy 3 months later and RAI almost 3 months after.

Several members had 2 or 3 Thy3 and after hemilobectomy histopathology was benign.


So long as it helps deliver a positive outcome for you! x


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