Iron deficiency and hair loss—Nothing new?

The document discussed a study on the relationship between iron deficiency (ID) and hair loss, specifically chronic telogen effluvium (CTE) and female pattern hair loss (FPHL). The study faced criticism for methodological inconsistencies, such as non-standardized blood sampling and lack of quantitative hair evaluation in control subjects. Despite these issues, the study found significant differences in iron levels between premenopausal women with FPHL or CTE and control subjects. However, the authors did not adequately address the unexpected finding of higher ID in controls compared to FPHL and CTE subjects. The study suggested that the hair follicle iron-regulating pathway might explain why only some iron-deficient women develop CTE, referencing the mask mouse model where iron supplementation corrected anemia and restored hair growth.