Iron is an important mineral necessary for many biologic pathways. Different levels of deficiency can occur in the athlete, resulting in symptoms that range from none to severe fatigue. Iron deficiency without anemia may adversely affect athletic performance. Causes of iron deficiency include poor intake, menstrual losses, gastrointestinal and genitourinary losses due to exercise-induced ischemia or organ movement, foot strike hemolysis, thermohemolysis, and sweat losses. A higher incidence of deficiency occurs in female athletes compared with males.