I am currently in the middle of writing a letter to my gp regarding the withdrawal of my treatment due to high serum b12 !!!!!!! This is in another post.
In the meantime I am supplementing with 2x 5000 Swansons Methylcobalamine daily, I think others have said that to make the best of the b12 you should also take vit b complex as well, do any of the high street stores have a good one at reasonable prices?