Although most of us in Western Society lean towards eating animal muscle rather than animal organs, there’s at least one good reason to try liver: It’s insanely dense in nutrients. That and, when prepared correctly, it’s delicious. A small portion of beef liver has: Vitamin B12, Vitamin B5, vitamin B6, niacin and folate, Vitamin B2, Vitamin A, Copper, Iron, phosphorus, zinc and selenium, and High-quality animal protein.