Pernicious Anaemia Society
15,513 members10,919 posts

B12 and atrial fibrillation

I have had arrhythmia for several years and was diagnosed with atrial fibrillation last June, have been on beta blockers since until last week when I decided to see if the medicine was contributing to my tiredness. I also started on a fairly high dose oral B12 or 15 mg per day ten days ago.

And upped my NDT to four grains as my body temp was on the low side or 36.5, I want to be around 36.8.

I haven't had a single heart flutter and certainly no AF in the past week and this is very unusual indeed. Does anyone know anything about B12 and AF? I have look a bit can't say I have found any reliable sources.

5 Replies

There are loads of research papers, it involves homocysteine and several B vitamins (B12, folate and B6) more than B12 only, see:


I had homocysteine tested a while ago and it was sort of mid range I think, and B12 was not too bad either. Interesting links though, you wonder why they don't test these things more frequently. I had expected homocysteine to be tested by cardiology but no, they didn't run many tests at all.


It could be that raising your dose of NDT helped your heart symptoms. I know that my own heart and cholesterol issues all but disappeared as soon as I was optimally treated with thyroxine and I was able to come off B12 depleting drugs.

Autoimmune thyroid problems, B12 and D deficiencies are usually interlinked (my sister has severe B12 def. and we both have autoimmune thyroid disease) and they impact on all the systems of the body, especially the thyroid - it is more than possible that adequate B12 and D3 could also see the thyroid becoming more normal. I hope these links help:

Most of us, apparently are now deficient in vitamin D owing to the use of sun screens, etc. and deficiency is implicated in diabetes too.


I admit I haven't taken enough vitamin D this winter but in the autumn my level was 148, the best in years. This has improved immensely since I started on NDT.

Oh well, possibly it's only the sun returning. I don't know but I suppose sun and daylight has an impact on hormones and stuff.

But I think it has to do with my supplementing with B12 as the change is huge.

I was on four grains for a while last year but had to cut down as it was too much then. I quit smoking five months ago and guess that could have had effect on thyroid hence the need for a higher dose?

1 like

I'm curious what is NDT I have had atrial fibrillation for years only got on medication and 2009 and now I'm thinking I should be on B12. Curious what more you've done overtime.


You may also like...