Thyroid UK
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Muscle pain

Hope someone can advise me ASAP plz! 5 days of taking 50mgs of levothyroxin but I have quite severe muscle pain that started yesterday it was my lower half, Calves burned like I'd run a marathon  (I wish) today it's mainly the top half. My Vit D & Iron are very low and B 12 is boarder line 200. Is this a side effect that will subside or should I stop taking the Levothyroxine?. I also have Fibro & have had various Ops in the last 2 yrs due to hand pain (last 2 on spine!) Grrr I need this like a hole in the head lol. Many Thanks Sandra.

7 Replies

I'm sorry you are having problems, which may well be due to having too low a dose of levothyroxine. Normally an increase of 25mcg of levo every six weeks is given until you are relieved of clinical symptoms.

I wonder if your fibro and other symptoms were actually caused by an undiagnosed hypothyroid problem? Your B12 is too low and you should supplement with B12, methylcobalamin sublingual B12 - Around 1,000 is the aim for B12. I doubt he would prescribe B12 and maybe not Vit D, which you should also supplement with Vit D3. (your GP may prescribe for this).  Your iron should be good and some members will tell you how to raise this if GP isn't helpful. Iron is needed to help convert T4 (levo) into T3 (the Active hormone required in all of our cells. B12 is a very important vitamin for it neurological effect and can also cause pain if deficient. Vit D is also extremely important. p.s. you cannot overdose with B12 as excess is excreted.

We probably take years to gradually become hypo so it stands to reason it will take a little while to reach an optimum of meds, i.e. a dose which makes you feel well with no symptoms. You can order through Amazon if you wish and this is self-explanatory.

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Thank you Shaws, I've posted a reply to Clutter explaining what's going on, but will say I'm puzzled as to why this is all happening since my Op in Dec (anterior Cervical cage & fushion due to nerve pain in hands) I will fish out the blood tests I had in November to compare, but I'm sure my TSH levels were all ok then? Irons been low for years but my B12 has defo dropped from 211 to 200 since then, Vit D wasn't tested for some reason?  Would one deficiency 


Sorry!..  Could one deficiency cause another? & could you shed some light on T3 not got a clue what I'm looking for on test result sheet lol. Vit D is 43 nmol/L I know is low!   My TSH is 5.26 borderline. What is TPO ?? Mines 964.9 ku/L positive. .?  & I know low iron 9ug/L. Thank you so much. 


A TSH of 5.26 is (I believe) out of range. The UK guidelines state not to prescribe until TSH is 10 by that time many people are so very unwell and don't know they really have hypothyroidism, a life-long disease which if undertreated/undiagnosed can cause more problems for us. Some doctors will prescribe due to symptoms.

In some countries with a TSH of around 3 with clinical symptoms you will get prescribed levothyroxine. 

A deficiency in vitamins/minerals can cause problems, B12 for instance is really a hormone which is vital for our nervous system and they now connect dementia/alzeimers to a deficiency. Dr Chandy says that many people diagnosed with MS actually have a B12 deficiency. And Vit D might also have an effect:-

Evidence is growing for a protective role of vitamin D in MS, and it remains an active area of research with a number of unanswered questions

If we have antibodies, as you do, you have an Autoimmune Thyroid Disease called Hashimoto's (the most common cause of hypothyroidism).

I have read that going gluten-free can reduce the antibodies as they are attacking the thyroid gland and eventually the person becomes hypothyroid.

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It may be your low vitamins and low thyroid causing the muscle pain as the Levothyroxine isn't likely to be properly absorbed for 7-10 days before it starts working.  Some times adverse effects are felt at first but they usually subside with a couple of weeks.

B12 200 is very low, 1,000 is optimal.  Supplement 5,000mcg methylcobalamin for a couple of months then reduce to a maintenance dose of 1,000mcg and take a B Complex vitamin too.

How low are your vitamin D and iron, and are you supplementing?


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.


Thank you so much for your reply, your time is much appreciated.  I've persevered 


Whoops Sent too soon ... I don't feel that much different still tired & in pain :( My iron is 9ug/l & my Vit D is 43nmol/L. I've had low iron forever (due to heavy monthly's) am I the only 56 yr old to still have them?  lol...  For the last 3 yrs I've suffered terrible hand pain, weakness & tingling, I've had both Carpal tunnel Ops, both thumb joint replacements. 2 cervical nerve release Ops back & front (last one done in Dec had a cage & fusion)  all to no avail! Thought the thyroid might have been affected due to op as scar is just right of the gland but surgeon says otherwise. I've been taking 200 ml iron & over the counter D but picking up prescribed Vit D tomorrow, 1 capsule a week, not sure what the dose is yet. I've asked for B 12 injections but because it's not under, doc doesn't seem concerned! I've tried the spray but I'm in agony a few hours later, the same with a lot of the remedies suggested. Your comment actually makes sense regarding feeling worse before you feel better! I just feel not with it, everythings such a struggle. Thanks again. 


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