What is the source of vitamin B 12 that vegetarians/vegans supplement their diet with?

B12 is found in bacteria, which in turn is found in water and soil. In the past, we could get this from the water we drank and the dirt on the vegetables and such that we ate. Unfortunately, everything has become so sterilized now that most people can no longer get it from these sources.

Meat eaters and vegetarians get their B12 from the animals and animal products, who still drink and eat the water and dirt with B12. Vegans have a wide variety of cereals, and soy and rice milks which are fortified with B12.

i think the answer is different for each person... I get my B12 from grains , nutritional yeast (a seasoning you can sprinkle on your food or cook with), soymilk, certain veggies, and proper cooking techniques (overcooking food kills b vitamins). there are tons of sources for b12 that vegans can choose from.

P.S. vitamins suck. i've never taken any in my life and i am the healthiest vegan i know

Yeast extract / marmite - nectar of the gods