Which of the Following Characteristics Is Shared by Iron and Zinc

Which of the following characteristics is shared by iron and zinc?

A) Neither functions in the maintenance of blood glucose
B) Neither is circulated from the pancreas to the intestines and back to the pancreas
C) Both are absorbed into intestinal mucosal cells and bound to metallothionein for transport first to the liver
D) Both are absorbed into intestinal epithelial cells but may then be lost by normal villus cell renewal processes