This may sound nuts...but I recall in nutrition class in university learning of a malady called 'hypervitaminA-osis'. Certain cultures were given to eating high amounts of fish eyes...which contain high levels of vitamin A.
This, in turn, would cause, I believe, liver and other prob lems.
I also recall thinking, "Why the F--- are they teaching us this shit?"
Well, now I know. I was able to sort of answer your question.
My tuition dollars working for me....