complete amino complexes and b12

Tis a question of "how much of it can be absorbed by humans".

For example absorption rate of vitamin A from animal sources is ~90%, but about 10% from veggies (if you use vegetable fat it's a bit higher, animal fat even more higher, cook it, juice it, the absorption rate plateaues at 30%; and technically it's not a vitamin A but something that will become a vitamin A when dissolved in fat) - and the amount of it in veggies is lower compared to animal byproducts.