There are plenty of meat eaters with critical vitamin insufficiencies, even of B12. Animals that are fed mostly a corn diet aren't exactly going to contain much

There are plenty of meat eaters with critical vitamin insufficiencies, even of B12. Animals that are fed mostly a corn diet aren't exactly going to contain much of micronutrients in their meat. Micronutrient supplements provide a much more reliable solution. I still rely on animals for hydrolyzed collagen and fish oil, but that's all.