I am bedbound. I am deficient in all b vitamins. I am trying to correct my b12 deficiency. I have low serum b12 and high urine MMA. Last year I took about 180 micro grams of methyl b12 sublingual. I had no bad effects the first time but three times after I would have burning muscles and was off my feet for a week. I am much sicker this year and am trying hydroxy b12 sublingual at just 5 micro grams. I feel wired, anxious and my ME is worse although some trouble moving my mouth is better. Does anyone know of such sensitivity to b12? Am I right to try and get this in my system or could it cause damage? My folate is low. Do I need to supplement this and how much? I am keeping my potassium up. Is there anything else that could be brought low? I am struggling to find anyone taking b12 in the amounts l am and wondering if I have a separate problem? I would appreciate any thoughts on this as I feel stuck. Thanks!