Iron is still a bit of a mystery in the human body:  while too little is a problem, so is too much.  In fact, an imbalance on either side of the spectrum is a disease, anemia (IDA - iron deficiency anemia)  and hemachromatosis.

Generally, when an adult is suffering from anemia, the first suspicion is some form of occult bleeding.  However, often no such cause can be determined.

This study shows a fascinating connection between IDA, and Helicobacter Pylori, the bug which is implicated in many ulcers.  In some of these cases, where previously it had been impossible to raise the patients' iron levels by ANY means, the levels adjusted themselves after H. Pylori was eradicated.

Eradicating H. Pylori May Help to Resolve Unexplained Iron Deficiency Anemia