What to watch with Transferrin and Sport?

Transferrin is an iron-transport protein. In athletes, transferrin levels can be affected by training load, diet, and blood loss (e.g., foot-strike hemolysis or sweat). Low transferrin saturation (<20 %) suggests iron deficiency, impairing oxygen delivery and performance. High saturation (>50 %) may indicate iron overload, which is harmful long-term. Direct-to-consumer tests often measure only transferrin, not ferritin or soluble transferrin receptor – insufficient for a full iron status assessment. Evidence for isolated transferrin in sports is weak; clinical iron panels are more reliable. Caution: iron supplementation without medical guidance can be dangerous if levels are already normal or high. See a sports medicine professional for personalized advice.