Hi everybody. I have been reading different posts on this forum with high interest. There is just so much about being B12 deficient, that I cant understand, or my Doctor can understand, for that matter. I have been reading for months, trying to figure out what to. About me: Started out with a stomach ache 3 years ago, my hair starting to fall out, feeling more tired, nothing too alarming, but it continued to worsen, and two years later I learned, that it was a B12 deficiency. At that time it was 192. In Denmark the common treatment for B12 deficiency is either an injection or an oral tablet in the form of cyanocobalamin. The doctor prescribed 1000 mcg of this oral tablet, called Betolvex. And OMG.. how it made me feel absolutely worse. Felt like I had the flu, extremely tired, glossitis developed on my tongue and the feeling of pressure to my brain. My Doctor never heard of such a thing happening, and assured me, that it was not from the supplement. Well ok....so I tried again weeks later - same thing happened. That's when I started reading about B12, and wow..there's a lot of different experiences out there!! I might add that I am smoking 10-15 cigarettes a day...I know..not good for you..... but maybe that was causing my reactions to the cyanocobalamin?? I read about this, but can no longer remember the explanation why (brainfog)..... - anyways, I've had no problems in the past with taking cyanocobalamin in multivitamins in smaller doses, now I do. I learned that, when I thought i just might be deficient i some of the other B vitamins. I took a B vitamin complex, again with cyanocobalamin, and it send me to the ER, after 3 doses, with heart palpilations (pulse 140), try mouth, increased thirst/urination, sweaty/cold palms and feet, vertigo, blurred vision, diarrhea. The Doctors thought I had a thyroid problem, of course..negative testing, then they thought I had had a blod clot in my heart, and kept me overnight for observation, again negative. They even brought me back in for a CT scan of my heart, days later, and could not find anything wrong, besides from a rapid pulse. No one would listen, that I had just been taking supplement containing cyanocobalamin. I started experimenting with methyl cobalamin, and did good, on small doses, very small, just 125 mcg. I increased slowly, and only got up til 750 mcg, and then..back to the heart palpilations etc. My Doctor thinks I must be allergic to something in the pills and send me to be checked for allergies. I waited for two months to get into the hospital to be tested, only to be told, that my symptoms didn't look anything like an allergic reaction. That's what I thought myself, two months wasted... My Doctor has told me straight out, that he does not know what to do with me. And I think...how can Doctors know so little about this. It's not rocket science, it's just a freeking vitamin deficiency, sorry...just getting a little frustration of my chest!! I have read about Fredds protocol, and thinking that it might be right for me. I don't think, that I necessarily have complex methylation problems. My own theory..and there has been quite a few of these...is that when I only take the B12, my symptoms are similar to folate deficiency. So I bought the B-complex from Pure Encapsulations, but I am actually a little scared of trying them, as I am feeling very weak now, with my B12 at a 140, and having a racing heart among other things, even though I have not been experienting with supplements for weeks now. So I am scared of feeling even worse. Should I just go ahead and take the vitamins, or can it make me worse?? I also think that I have to imrpove my gut health, I am already eating a fairly healthy diet, but more friut than veggies, and very little fish. So I will also be starting on a good quality Probitic. Hoping to hear from you.