Vegan diets may be deficient in carnosine, anserine, creatine, and 4-hydroxyproline.

“so many beneficial things that he's leaving out and things that are clearly present in Animal Foods must be supplemented so if you believe your vegan diet is better for longevity but in order to get optimal you must take multiple supplements many supplements to make up for the nutrient deficiencies in your vegan diet and there is correspond l a simple easy elegant evolutionarily consistent solution to getting those nutrients namely eating meat and organs that you've left out of your vegan diet”