Gramaisc
Forum O. G.
B12 is required in very small quantities, slightly more than none is enough, and most people will have months, or years, stored up. There are those who believe that you can get enough from bacteria, if you aren't too scrupulous with the cleaning regimes. Some converts can find themselves caught out, if they are using their stores whilst they settle into the new regime and feel that everything is OK, then start to run short as the supplies aren't topped up.