I have RA but also a low B12. The doctor has prescribed 50mcg cyanocobalamin daily via a phone call, without discussing my symptoms. This didn't seem enough so I went back to discuss my symtoms. His reaction was to suggest I have anxiety problems ! Ermmm...isn't that a low b12 symtom?? I respect my doctor and so declined the medication offered for anxiety politely, and left. I researched and found Solgar Sublingual Methylcobalamin 1000mcg which I subsiquently bought from town in Holland and Barrett. I took 1 a day for about a week- some symptoms seemed to be improving. Feeling guilty I took them into my chemist (who is great!) to ask his opinion. He said that as these come under a food supliment and not medical , there is nothing to ensure that what is in the bottle is a) Methylcobalamin b) containing as much as it says c) what it might be mixed with! He explained about a colleague who looked into something similar which, out of nearly 50 different brands, none of them contained what they were supposed too!!
Confusion is...I know the 50mcg is not going to touch my symptoms but 1000mcg of 'who knows what!' might not either. I'm not due another b12 blood test until May and I'm not at my rheumatologist until April.