Most Americans, if they consume adequate calories via a balanced diet, obtain more-than-sufficient amounts of iron, negating the need for additional iron from supplements. Lieberman & Bruning (1990) recommend an Optimum Daily Intake (ODI) of 15-25 mg for men and 20-30 mg for women. It is very easy to exceed these values from food alone. If an athlete consumes excessive amounts above Recommended Daily Allowance (RDA) levels of dietary iron—which ranges from 8 - 27 mg daily, depending on gender and age—they may experience premature fatigue and, potentially, more serious general health issues.
According to a well-respected source, "Most people have too much iron in their body. Excess iron generates massive free radical reactions. Human epidemiological studies show that those with high iron levels are far more likely to contract cancer and heart disease. A growing body of evidence implicates iron in neurological disorders such as Parkinson's disease."
Iron is an extremely important nutrient, especially for endurance athletes. An iron deficiency can negatively affect oxygen transport to the muscles if below-levels of hemoglobin are detected. An iron deficiency can also impair energy production if myoglobin and mitochondrial enzymes are sub-normal. However, too much iron can cause serious health issues, as outlined above. Therefore, because the overwhelming majority of Americans consume sufficient amounts of iron from their diet, and because of the negative health issues associated with excess iron intake, Premium Insurance Caps do not contain iron.
If you aren't sure about your iron status, a CBC (Complete Blood Count)/Chemistry Profile blood test will determine what your iron status is and whether supplementation is necessary.
