"The Photographs above are of encrusted fecal matter removed from the colon wall. This black sludge is the gradual build up of unnatural, toxic thick mucous-like substance created by the body in an effort to protect itself from unhealthy foods, stress, drugs, pesticides, etc. This substance may accumulate until it is several inches thick and reaches the entire length of the stomach, small intestines and colon. This layer of mucoid plague prevents the body from properly assimilating vitamins, minerals and food nutrients. Autopsies have revealed colons that were from 9" to 18" in diameter, because they were so packed with layers of this encrusted mucoid fecal matter....some weighing up to 40 pounds! (a healthy colon weighs about 4 lbs.)"

I haven't seen any specific evidence that the this substance will reduce B12 intake, but I find it very likely that there is a connection. Hopefully most of us aren't in as bad shape as the owner of the substance above were, but still....

There are lots of studies showing how healthy eating plants is. But these studies are (almost always) based on people who grew up on a standard diet. Why isn't there more research on people who grew up as heathy plant eaters? That would give a lot more interesting and revealing info on the benefits of not eating animal products and junk food.