Why is too much iron dangerous?

a. Transferrin, which carries iron, causes cellular swelling and lysis.
b. The oxygen carried by excess iron oxidizes neurologic cells.
c. Iron's breakdown products cause excretion of vitamins C and E.
d. Free radicals and superoxide formed from ferrous iron plus oxygen damage cell membranes.

ANS: D
When iron exceeds storage capacity, ferrous iron accumulates in cells. Ferrous iron is easily oxidized and in so doing generates superoxide and other free radicals, which are very damaging to cell membranes, mitochondria, and other cell organelles. Cell death and eventual possible organ failure are consequences.