Well sure. But that wouldnt really apply to people who never used synthetic A or acne meds, right? I wouldnt eat liver every day, no way, but I think once a week raw beef liver sounds like one of the most strongest "supplements" there is. I have ceased to use supplements anyway, since they never brought any lasting benefit IMO. And if human race managed without them for 99.9% of our time, I see no reason why we would need to ingest pills now eitherIf you overdosed on venA supplements like @youngsinatra did, then there is a very good reason to avoid liver.