If you feel you are deficient in B12...it would probably be more healthful to get the B12 from actual wholefoods. (read the article on Vitamins at www.thedoctorwithin.com)
I looked into it at one point and found a whole list of foods that are high in B12...but all I can remember now is Brewer's Yeast (get it at the healthfood store in bulk) and Miso Soup. Read my post below. (*it's important to only buy unpasteurized miso*)