The Benefits of Vitamin B12 Injections Many people believe that vitamin B12 is only found in animal products, but that's a misconception. B12 is actually produced by bacteria in the soil, and animals get their B12 by consuming The B12 in meat is from supplements given to the cows.so why not just take the supplement directly : r vegan People love to bring up B12 like it's a reason to eat meat. But here's the irony Even meat eaters can be deficient in B12. That's because B12 comes from bacteria in