Thyroid UK
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New hypo, old PA - advice please!

Hello all. I'm a newbie and am just hoping to pick your brains...

I was diagnosed with pernicious anaemia aged 21 (now 38) and was on B12 injections for years until a GP advised that my levels were "always high when tested" and this could "be dangerous". My injections were stopped 3 years ago and, to be honest, I went along with it as I didn't know any better.

I've been light headed / fainty / nauseous / etc as long as I can remember and have had joint pain on and off for ages, so I can't honestly say that I noticed any significant new symptoms other than developing really annoying tinnitus. I did acknowledge that I felt very low and was therefore referred for CBT, which undoubtedly helped with some unhelpful thoughts about being useless, etc... but I do remember telling the therapist that I have tried very hard for years with positive thinking and my biggest struggle is that my body feels like a dead weight I have to drag round and I was just started on antidepressants.

I reviewed my diet and exercise etc at the start of the year, determined to feel fabulous (!!) but I ended up about 2 months ago feeling like I could barely get out of bed I was so tired (as well as brain fog, etc). I asked my GP for a blood test and this showed TSH 39.7 T4 8.8 as well as my B12 levels having dropped (unsurprisingly!) and low vitamin D.

So! The latest chapter is that I have had the loading dose again for B12 after finding this site and insisting, and have started thyroxine and Vitamin D. I am starting to feel a bit less tired but today's check bloods are not yet within normal ranges so there may be more improvement to come. Still the bloody tinnitus though!

One really puzzling thing is that, although I have a low temperature and have put on over a stone, my pulse has gone from 50-60bpm at rest 3 years ago to nearer 90bpm. I am doing less exercise than I was (well, none at all), but even so this seems weird. It was raised at the doctors today so she has requested an ECG and referred me to an endocrinologist.

Please could I ask for your advice, lovely people, about a) the pulse thing and b) about how to get the best out of the endocrinology referral. Am so determined to find out how I can feel as well as is possible for me, but looking back it was so easy to get fobbed off and dismissed and I want to learn from this.

Thank you for any and all suggestions.

13 Replies

Welcome to the forum, Sisalcat. is dedicated to PA and B12 deficiency.

What are the results and ranges (figures in brackets after results) of the latest blood tests? Tinnitus often improves when thyroid levels are optimal. Your thyroid levels being too low is probably why your resting heart rate is higher but 60-100 is normal so 90 isn't anything to be concerned about.

The goal of Levothyroxine is to restore the patient to euthyroid status. For most patients that will be when TSH is 1.0 or lower with FT4 in the upper range. FT4 needs to be in the upper range in order that sufficient T3 is converted. Read Treatment Options in

It's not uncommon for hypothyroid patients to have deficient/low vitamins and minerals so it may be worth asking your GP to check ferritin, and having one autoimmune disease increases the likelihood of having others so ask your GP to test thyroid peroxidase antibodies to see whether your hypothyroidism is autoimmune in nature.


Thanks Clutter. I don't have the latest test results unfortunately but will try and get them. Am not too worried about the pulse - as you point out it is in the normal range - just feels so damn odd as it is so different from what I am used to hearing (especially at night)! That is great news regarding the tinnitus, will keep my fingers crossed that it goes away in due course :-) I have commonly been low in ferritin / folate / etc over the years as you say - the same GP that stopped the B12 told me there was no evidence that this causes symptoms as long as you Hb doesn't drop (but I no longer trust anything that came out of her mouth!). Might suggest a retest...

Thank you



I hope you're not still being treated by a GP who doesn't think PA patients need B12 injections :o


Hi. As clutter suggests, go on to the PA community for information. There are no studies to say that high levels of b12 are dangerous. In fact, they use extremely high doses to treat patients with cyanide poisoning. The PA society say that your b12 level shouldn't really be under 1000, to prevent both neurological and cognitive impairment.

Doctors don't really understand the issue at all. As you have PA treatment is for life and should not be stopped. Injections don't'cure' PA or anyone else who has trouble with b12 absorption. It just keeps symptoms at bay. If you look at the guidelines from the British Committee on Standards in Haematology it states this as well as all the flaws with the test. Once you are on treatment further testing is irrelevant. Your GP should've read this, but often don't. If your GP fails to keep up the injections, the PA society can step in and help.

If you cluck on my communities above, then browse communities, you will find the PA community. I can't absorb b12 due to low stomach acid, common with hypothyroidism. As you have both conditions your b12 will be very low. Good luck.

Should say click not cluck! :-)

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LtAngua52 would be greatful if you could provide the exact reference to B12 levels being over 1000. As far as I am aware the PA has not made any statement about levels needing to be above 1000 to prevent neurological and cognitive impairment.

I am aware that a study was done of members and where they felt their levels needed to be to function and the average came out as 1000 but that is a very different thing.


I've read this from members on the PA forum, plus it's in the sally pacholok book. I think it's other references too that have been mentioned on the PA forum too.


Sorry, do you have any more specific references.

Important to remember that these forums are support and not solid medical advice.

I will try to have a look at the book you mention but personally I don't remember reading a statement that levels needed to be 1000. I do remember a statement that those with B12 absorption problems who are trying to control them with B12 taken orally or sublingually need to take at least 1000mcg a day but that is something quite different.


'...we believe normal serum B12 levels should be greater than 550pg/ml. For brain and nervous system health and prevention of disease in older adults, serum B12 levels should be maintained near or above 1,000 pg/ml.

From 'Could it be B12? An Epidemic of Misdiagnoses.' 2nd edition. Sally Pacholok & Jeffrey Stuart. 2011. Quill Driver Books. Fresno, California. Page 11.


thanks but the key phrase there is 'older adults' so it isn't a general level for everyone and again it would be done in the context of whether a patient was symptomatic.


Meant to say b12 is water soluble so excess is just excreted. It is not toxic, despite what doctors say. Tinnitus is another PA/low b12 symptom too. There are many symptoms, check them out on the PA site.

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Cheers both. I had the good fortune to be directed to the PAS website just after starting thyroxine...cue a stern phone call to Doctors that resulted in restarting the B12! Kicking myself to think I got talked into giving it up in the first place but back on track now :-D

Awesome to find such a helpful forum, thank you for your help


Surely your B12 will always be high when you are having injections as the test only shows what's in the blood, not the cells. I don't know of any studies that show high B12 being dangerous. Do doctors actually study anything at all or just spent their years at uni getting drunk? Low ferritin can cause a fast pulse so get that tested - needs to be at leat 70 for thyroid meds to work.


Hi Sisalcat - certainly does sound as if your GP is rather ignorant when it comes to vitamins.

You need folate to process B12 so if your folate levels so low levels are going to lead to pretty much the same symptoms as B12 deficiency.

You might try pointing them at this website in relation to B12



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