Thyroid UK
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Neuropathy - too little B12 or too much B6?

Hi there, I posted about this yesterday but am still a little confused about vitamins, so I'm hoping for some suggestions as how to best handle the situation.

I'm taking 1000mcg sublingual B12 methylcobalamin daily to support thyroid. Plus a B complex tablet daily. I have neuropathy and joint pain. So this is the quandary - is it due to too little B12 (my February B12 test result was 490, the upper limit being 750) OR is it too much B6 from the B-Complex tablets?

If the B12 sublingual tablet is water soluble and the excess gets peed out, then is it okay to continue with the B12? Is it better to have too much B12 - maybe 490 is still considered too low a level and it's causing the neuropathy?

The B6 level in the tablets is 35mg.

The B6 RDA for women over 50 years old is 1.5mg. Yet 'the literature' says that B6 isn't problematic unless taking more than 100mg a day. So I'm bewildered, and scared by the numbness/tingling/heat etc in my hands and feet. I never had any of these symptoms until I started supplementing with B Vitamins back in November 2016. I just want to stop all the supplements and want this neuropathy to go away :(

11 Replies

What is your vitamin D level? What is your ferritin level? What is your folate level?

The reason I'm asking is people have joint pain from low/insufficient vitamin D levels. And can have random numbness, tingling and heat from having low/insufficient levels of iron, vitamin D and folate. In other words while specific vitamin and mineral deficiencies are linked to certain symptoms and signs, other vitamin and minerals deficiencies can also cause them. If

Also be aware the RDA is the minimum level to stop the 'average' women being ill. It is not the level that gives you optimal health.

Edited to say - seen your high ferritin level. High ferritin can also cause the problems you have.


hi bluebug

In February, Vitamin D was 91 (upper limit 175) and Folate was 45.4 (upper limit 60.8)

Yes, Ferritin was very high - nearly 4 times the upper limit. I didn't know excess ferritin could cause neuropathy too. I'll look into that.

I guess I'll just have to sit it out till I can see my GP later this month. I'm a bit of a worrier! Thanks


Unfortunately when they put the symptoms of too high iron levels they only put some of them in.

However they do state you can get the same symptoms from having low levels as high levels.


You might be better trying vitamin B complex - see this article - B5 is implicated in neuropathy

Apparently it's best to supplement al the B's together

Also very important to know your vitamin D level - very common to be low with Hashimoto's.


Thank you for this very informative link SlowDragon. Reading it has helped explain such a lot. I will be drawing on the information as I continue to improve my health without relying on prescription meds/chemicals.


Hi slow Dragon, yes my french GP used to prescribe me monthly liquid D3. Since back here I supplement D3 and GP okayed it. I'd prefer the liquid version though because it gets absorbed more quickly by the body. Sambs.


I found I couldn't tolerate any vitamin D supplement unless at relatively high dose (6000iu daily minimum)

Any less would give extreme bone/muscle pain.

Tried taking none for 3-4 months, but levels fell sharply & became more hypo.

About a month ago I started using a vitamin D lamp every morning. Slowly built up (so far) to 8 minutes each day - so far, so good...... in fact seems astonishing

It wasn't cheap & I was extremely sceptical it would do anything. Very Pleasantly surprised 😳

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I've also just looked at the link SlowDragon - quite amazing, Im learning more and more every time I follow up on anything! So many of the symptoms in the article I've always put down to the effects of my Brain Haemorrhage 4 yrs ago this week - although my own later personal research could link slowly link all my conditions. I've never thought I had I had any effects of being HypoThyroid (now it's Hashimoto's) except for the hair thinning and dry skin, mainly on my feet and legs initially but I certainly shed skin cells on my stomach. I also have Vitiligo, most evident on my heels, lower legs, arms and hands.

My most basic problem is usually remembering the day after, detail of something I've read days or weeks earlier when it takes a long time to process the Information, which means I don't act on it!


I get joint pain when I don't have enough thyroid. My shoulders particularly but I can feel the difference even in the hands when my thyroid is a problem. It goes when I take enough NDT .

With B12 If they treat you when below 500 in Japan then that could be the problem? This is all so complex, good luck.

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If we take too much B12, I believe excess is excreted and it is recommended that the upper number B12 should be around 1,000. Some labs have a lower figure for top of the range.

If Marz reads your post she is good at answering re the B's.

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recommendations on upper limits for B6 vary from 100mg in US to 25mg from EFSA (europe) to 12.5mg in UK (if remember correctly).

RDA is the amount recommended for general health so can be significantly different from upper limits which address concerns about 'overdosing'.

link to EFSA recommendations for upper limits - which goes into a lot of detail about reasons

On B12: serum B12 is problematic if used as a single indicator - 25% of those in normal range will be deficient, but it is also the case that 5% of those below the normal range won't actually be deficient - people vary a lot in how much B12 they need

- symptoms need to be taken into consideration - though can be difficult to evaluate symptoms where other conditions exist.

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