What is the potential importance of taking iron?

Iron deficiency is not uncommon among some groups of healthy people, including some vegetarians, menstruating girls and women,pregnant women, and female and adolescent athletes. Nonetheless, many people in these groups are not iron deficient and excessive iron intake has been associated in some studies with heart disease,some cancers, diabetes,increased risk of infection,and exacerbation of rheumatoid arthritis. While none of these links has yet been proven, people should avoid iron supplements unless they have been diagnosed with having, or being at high risk of, iron deficiency.