Iron absorption by healthy women is not associated with either serum or urinary prohepcidin

BACKGROUND: Although hepcidin is proposed as a regulator of iron absorption, this has not been assessed in humans. OBJECTIVE: Our objective was to assess the relation between serum or urinary prohepcidin and iron absorption in healthy premenopausal women. DESIGN: The subjects were 28 healthy women aged 22-51 y with normal hemoglobin concentrations (120-152 g/L). Absorption of 0.5 mg Fe with 0.2 microCi 59Fe tracer, both as FeSO4, was measured by whole-body scintillation counting 13 d after oral administration. Fasting blood and urine samples were collected the day of and 16 wk after the absorption measurement. Serum and urinary prohepcidin concentrations were measured by an enzyme-linked immunosorbent assay by using an antibody against amino acid residues 28-47 of the proregion. RESULTS: Mean (+/-SD) iron absorption was 36 +/- 19% (range: 4-81%), and serum ferritin (geometric x) was 27 microg/L (range: 4-122 microg/L), as commonly observed in healthy premenopausal women. Serum prohepcidin was 196 microg/L (range: 99-376 microg/L) and, in contrast with urinary prohepcidin, was relatively consistent for the women between 0 and 16 wk. Serum prohepcidin correlated directly with serum ferritin (R2 = 0.28, P < 0.01) but was unrelated to 59Fe absorption, in contrast to serum ferritin (R2 = 0.33, P < 0.01). CONCLUSIONS: Serum prohepcidin concentrations were relatively stable within subjects and correlated with serum ferritin. However, unlike serum ferritin, neither serum nor urinary prohepcidin concentrations were related to iron absorption in healthy women.