As I've noted in other posts, I've been suffering terribly with palpitations and shortness of breath. I have been supplementing with potassium but still have not gotten relief. Palpitations have been so bad at night, I've not been able to sleep. Then it dawned on me that I was having the same symptoms as being hyperthyroid. I was diagnosed with hypo in 2006. I have been on a low dose of natural thyroid meds for a while now. I decided to not take my afternoon dose yesterday to see what would happen. Wow, the palpitations almost totally stopped. I slept soundly for the first time in quite a while. My breathing is so much better but still not 100%. I decided I wouldn't take my morning dose today either and see if breathing and palps improved 100%. Still too early to tell yet. I know from reading there is a direct correlation between B12 supplementation and hypothyroidism. Is there anyone here who has been able to get off their thyroid meds from using B12? If not, have you heard of that happening?