All forms of Vitamin B12 require the intrinsic factor for absorption, which in turn requires adequate stomach acid and an acid pH of 2.0 or less. Only microorganisms are capable of incorporating cobalt into Vitamin B12. Since cobalamin is not found in Vegetarian food sources, herbivores get Vitamin B12 by eating plants that are infested with insects, or by actively eating feces to meet Vit B12 requirements, while in ruminants, the microbes fermenting and digesting plant material in the rumen, incorporate cobalt into Vitamin B12, which is subsequently absorbed and utilized... Full Text