Iron status in athletes. An update.

Area of Science:

• Sports Medicine
• Nutritional Science
• Exercise Physiology

Background:

• Athletes' iron status is increasingly studied, yet the interpretation of observed changes remains controversial.
• Distinguishing true iron deficiency from physiological exercise responses is crucial for appropriate intervention.
• Iron deficiency is prevalent in the general population, especially women, highlighting its public health significance.

Purpose of the Study:

• To critically evaluate the significance of apparent iron deficiency in athletes.
• To differentiate between physiological adaptations to exercise and genuine iron deficiency.
• To provide evidence-based recommendations for monitoring and managing iron status in athletes.

Main Methods:

• Review of existing literature on iron status parameters (serum ferritin, hemoglobin, haptoglobin, bilirubin) in athletes.
• Analysis of studies investigating exercise-induced changes in iron metabolism and indicators of hemolysis.
• Examination of evidence for dietary iron intake deficiencies and blood loss in athletes.

Main Results:

• Exercise can alter iron status indicators like serum ferritin and hemoglobin, and affect hemolysis markers.
• Physiological responses such as plasma volume expansion and iron redistribution may influence iron status parameters.
• Evidence also supports dietary iron inadequacy and gastrointestinal/urinary blood loss in athletes, contributing to true deficiency.

Conclusions:

• Apparent reductions in iron status markers with exercise may be misleading due to physiological adaptations.
• However, genuine iron deficiency, driven by inadequate intake and blood loss, is also evident in athletes.
• Continued monitoring of athletes' iron status is warranted, with iron replacement therapy recommended when deficiency is confirmed.