You mention starting on 1000mcg of cyanocobalamin. I do believe you should be taking 1000 or more of B12
methylcobalamin versus cyanocobalamin.
I have been taking this methyl kind since last spring/summer, as much as 3000mcg a day sometimes, and my last blood test had my B12 over 1000. Have you read any of Rose's information on B12 -
http://roseannster.googlepages.com/home.
I order mine through iHerb and use the Jarrow brand -
http://www.iherb.com/store/ProductsL...ethylcobalamin
I hope this information is helpful to you.