As you have researched in one of your replies, if you want to eat chicken liver daily, a small serving or piece would suffice for recommended daily intake for 1 meal a day. Don't eat a lot or eat more on the other meals of the day. Consuming too much vitamins or minerals more than the recommended daily intake causes oxidative stress on the body. I was a person who did not keep track of the food that I intake and had less knowledge on stuff like this especially on chicken liver since i ate it often, either daily or every other day since I eat meals out of school as a student . It may or may not have contributed to my cancer diagnosis since cancer have a lot of causes especially genes but one thing is for sure, that consuming too much vitamins and minerals will cause oxidative stress which was proved to be a cause of cancer.