In fact many elite athletes, especially females, develop hyperthyroidism.
Iron deficiency seems to be a core mineral deficiency in overtraining.
Khaled S, Brun JF, Wagner A, Mercier J, Bringer J, Prefaut C Service d'Exploration Physiologique des Hormones et des Metabolismes, CHRU de Montpellier, France. These data suggest that mild iron deficiency as commonly seen in athletes, before anemia occurs, is associated with an increase in plasma viscosity and RBC aggregation, together with an increased subjective feeling of exercise overload. Clarkson PM Department of Exercise Science, University of Massachusetts, Amherst 01003. This paper examines whether mineral supplements are necessary for athletes, and whether these supplements will enhance performance. Calcium supplements are important for the health of bones.