HAMP and nutritional disorder: Choi et al. [3] suggested that serum hepcidin concentration <6.895 ng/mL had sensitivity of 79.2% and specificity of 82.8% for diagnosing iron deficiency, and hepcidin <2.735 ng/mL had sensitivity of 88.1% and specificity of 88.2% for diagnosing iron deficiency anemia.