Hi,
I just read all the posts under your question and about your body not absorbing the B12. I think the question here should be WHY is your body not absorbing? If you could find out why and could solve that problem then you would not need the shots.
If I were guessing, I would say constipation.
Some vegetarian sources for B12 are kelp (probably most sea vegetables), alfalfa (sprouts or capsule form), bladderwrack, & hops.