Levothyroxine and B12 possible interactions

[yorkshiregirl4]

I have been taking Levothyroxine for many years and believe that the symptoms I experience for both too much or too little Levothyroxine are identical. When I experience an increased pulse rate that can be because of either too much of too little Levothyroxine but keeping my dose fixed this problem is usually avoided.

As I have been increasing my B12 levels with daily SI I am now noticing an occasional increased pulse rate and this has led my to wonder if the increased B12 levels might be improving my thyroid function such that I do not need as much Levothyroxine or is it that I could need more Levothyroxine to in some way support the increased higher level of B12?

I am wondering if anyone has experienced something similar to this or has anything helpful to suggest.

[FancyPants54]

The only sensible thing to do at this point is to take a full thyroid blood test to include TSH, FT4 and FT3.

If you are a member of the Thyroid board on here then you probably know the protocol for testing. Before 9am, 24hrs after last Levo and 12-15 hours after last T3. Doses are adjusted the day before to fit into this pattern. Nothing but water to eat or drink before the test and no meds until after the blood is drawn.

Most of us have given up asking our GPs for thyroid bloods because they almost always fail to do FT4 and FT3. So the cheapest option is Monitor my Health, which is an NHS lab in Exeter but who will run the tests for us for sensible price. If you get the link from Thyroid UK web site (under tests) there is a discount code to get 10% off.

Then look at your results and see if you think things have improved or got worse. Share the results over there and see if anyone has found a link to B12 with their thyroid results. It's a very active board and has some excellent well experienced people on it.

[yorkshiregirl4 in reply to FancyPants54]

Thank you so much for your suggestions. I have not been on the thyroid section of HealthUnlocked yet. I have had difficulty getting blood tests undertaken by my GP, just as you have pointed out. I will certainly check out your suggestion of the NHS lab in Exeter. Thanks.

[FancyPants54 in reply to yorkshiregirl4]

Many of us have given up with GPs where thyroid is concerned. We do our own tests and adjust our own medication and if we can't get the medication from the NHS at the right level or at all, we buy it. It should not be that way, but it is for many.

One thing I've learned from years of struggling with it, you can't guess thyroid. Symptoms of too much and too little are often pretty much identical for me. I have to test. You need to be on the same dose of meds 6-8 weeks before testing. Any adjustments made need another 6-8 weeks to settle before retesting.

[yorkshiregirl4 in reply to FancyPants54]

Thanks for your help and advice which is very useful.

[Jillymo]

I am on thyroxine and daily B12 injections but cant say I have experienced any change with pulse rate.

You might find you get more answer's by posting the same query on Thyroid UK. It's worth trying to see what response you get. I would take FancyPants54's advice and get your levels checked then pop the results on Thyroid UK together with the Lab Margins.

[yorkshiregirl4]

Many thanks for your reply Jillymo. I have already looked at the private blood tests website recommended by FancyPants54 so will take this good advice from you both. Thanks.

[Jo55]

hi I was wondering the same although the other way round. Just before my injection, especially if I’m really struggling, my resting heart rate goes up, I get palpitations and feel generally unwell. This seems to start about an hour or so after taking my thyroxine and tends to wear off a bit by evening. Yesterday I forgot to take my thyroxine and didn’t feel anywhere near so bad so assume I’m going overactive when this happens. As I have my injection Tuesday I’m going to wait till after and see if things calm down again.

Hope you sort your thyroid problems out

[yorkshiregirl4 in reply to Jo55]

Sorry to hear you are experiencing these difficulties. It is so difficult to keep "on an even keel". Perhaps we don't need as much thyroxine when the B12 has started to improve things including the thyroid gland. It is so challenging when there is so little understanding from medics and the time required to have a further thyroid blood test is 6-8 weeks on a new dose. Let me know how you get on. Best wishes.

[Cornwaller]

My experience is very similar to yours. Improved b12 status reduced need for thyroid meds and for me too much thyroid gave me similar symptoms to too little.

[yorkshiregirl4 in reply to Cornwaller]

Whilst I am sorry you have had to resolve this similar problem it is so reassuring when I come across someone else who has had a similar difficulty to resolve. It is so reassuring and is a short cut for me when we both have the same type of symptoms with too much or too little thyroxine. It is so brilliant that members on this site are so willing to share experiences and information and makes a massive difference when not knowing where to turn. Many thanks for your kind reply and I will continue on my lower level of Levothyroxine.