We wanted to discuss vitamin B12 and dispel the wrong information we often see being repeated. First of all vitamin B12 does not come from animals at all. It is the only vitamin synthesized exclusively by microorganisms, and is found in soil, plants and other organism like mushrooms. Just like many other animals we also make our own vitamin B12 in our guts. However, the place where we make it in our intestine is after the place that is able to absorb it, hence why we need an external source.
Our latest update on vitamin B12 can be found here.