Hi jodimarierita,
Yes, iron can cause serious problems when taken long term, if not needed. I would suggest having a group of blood tests called an iron panel done, to make sure you really need iron. No one should be on long term iron supplements without having these tests done, and if iron deficiency is found, then the tests should be repeated periodically until the condition is corrected and the iron is discontinued. If the tests do show that you are still deficient, then another form of iron may be necessary. Also, taking vitamin C with iron aids in absorption.