Iron and Hair Loss in Women: What Is Deficiency? This Is the Real Question!

The letter by Dr. Rushton and colleagues addresses a critical issue raised in a review article about the role of iron in hair loss in women, specifically questioning what constitutes iron deficiency. They argue that the current lower reference limits for serum ferritin, which are used to estimate iron stores and diagnose iron deficiency, may be too low because they are derived from populations that include a significant number of iron-deficient individuals. They cite studies indicating that a serum ferritin level above 70 µg/L is more indicative of adequate iron stores, as opposed to the lower levels often used in clinical practice. The authors suggest that using these inadequate reference limits could lead to misdiagnosis of iron status in patients with hair loss, potentially affecting the design and outcomes of clinical trials on iron deficiency and hair loss. They advocate for a reevaluation of the reference ranges for serum ferritin and hemoglobin, especially in menstruating women, to ensure that iron therapy is appropriately administered for conditions like unexplained chronic telogen effluvium.