Vitamin B12 is also called cyanocobalamin. It is the only B vitamin that is not present in any of the vegetables. The most common sources of vitamin B12 are liver, eggs, cheese, meat, kidneys, and milk.
A vegan diet is the one that does not include any food product from animal sources. It also does not include any dairy products. Since vitamin B12 is found only in food products of animal origin and in dairy products, Dylan would not be able to obtain vitamin B12 from the vegan diet.