Thank you for the replies. I have been trying to create a doubt about the "B12 must come from animal products" issue belief since I started exploring plant-based diets. I have managed to find that everything a human needs can be obtained “naturally” from fruits, vegetables, beans and nuts - except B12. It is an essential nutrient for humans so I am trying to figure out how we maintained a supply of B12 before the advent of vitamin supplements. The answer always seems to come full circle back to animal products. Of course, today it is a very different type of food supply of animal products than it was 100 years ago. Today these food sources are polluted with steroids, antibiotics, preservatives, etc and are produced in a way that should bring great shame to humans.
In any event, these are my questions so far:
1. If we get our B12 from animals, where do they get their B12 from? In other words, the animals we get our B12 from are mostly vegetarian ie; cows, pigs, chickens, etc. Are they getting it from vegetation or do their bodies produce B12?
2. If they are getting it from vegetation, why can’t we get it from vegetation, especially being on a plant-based diet?
And further, with respect to number 1 above, it’s interesting that most humans are not getting B12 from animals that are meat eaters i.e. lions and tigers, but rather from animals that are vegetarians/vegans. It’s all very thought provoking and interesting. I don’t know what it all means.
Thanks for the replies. And yes, I'll take any links you have that can shed light on this.