Hi! I am new to this forum and I feel like I might've won the lottery. I have been ill for 2.5 years. In Oct. of 2005, my doc prescribed Tequin for my supposed Legionnaires Disease (didn't have it in hindsight). I have been on disability ever since. Pre-Tequin I was a physically active, career, family woman. Since I've taken this antbiotic I have never been the same since. However, I have been dx'd since then with low potassium (I was hospitalized for 5 days due to that), low sodium, low ferritin (results was 6), low thyroid, and now my Naturopath says I have low B12. I believe in my heart of hearts, this has been part of my problem for the last 2.5 years. For the first time my B12 was tested January 30, 2008 and my result was 507 (range 200-900), and then retested in March of 353. I have been battling Neurological symtoms since taking Tequin. I have had nerve twitches, extreme fatigue, very, very sensitive to noises, cold feet, irritability, personality change. I feel noises in my forehead and throughout my body. My reflexes are very, very strong (I almost kick myself lff of the table). It's like my nervous system is highly exciteable. Since January I have experienced tingling feet and tingling hands, that gloved feeling (like I'm touching something, but I'm not) and my feet look purple like they are not getting any circulation. I have had a headache for 2.5 years. I have mental fog, and my memory is terrible. I have lost muscle mass also, even though I weigh the same. My ND put on methyl-b12 1000 mcg. I took 1000 mcg for 2 weeks, and bumped it up to 2000 mcg for one week. I got this horrible, horrible worse headache. My methyl-b12 was not Jarrows. I then tried one day of taking 5 lozenges and my headache was worse, and it put me to sleep. I slept for 12 hours that night. Last week I tried a B12 injection, the cyanaxo type, and that gave me huge headache, but 2 days later, I feel a little better. My question is, I feel there is no doubt that I need to raise my B12 level, and it's contributing to my health problems, but I seem to be very sensitive to B12. Is this possible? I just bought Jarrow's, and I took 1000 mcg yesterday and one today. I would like to take more, but when I took more last time, it really made me sick, as well as the injection. My ND earlier this week, too my MMA and homocysteine test. I don't have the results from that yet. I really feel this is a missing piece of the puzzle, so that I can feel better again. I can't take more than 1000 mcg. a day. Has anyone else had this happen to them. I just want to get well, and I think the more I take, the faster I will. Any thoughts? Thanks, and I appreciate any advice.