Hepcidin was the main determinant of an SFH <10th centile (CLAP) and an SFH <3rd centile (INTERGROWTH), and hepcidin was associated with indicators of inflammation (ferritin, IL-17, CRP) and indirect indicators of hypovolemia and malnutrition (lower urinary pH and higher intake of MNS). Here, HAMP is linked to nutritional deficiency disease.