FGF23 and hypophosphatemia: In fact, hypophosphatemia with impaired tubular reabsorption, low 1,25(OH)2 vitamin D and high FGF23 levels has been reported in anaemic patients with normal renal function treated with saccharated ferric oxide or iron polymaltose [15,16], supporting an etiologic role of FGF23 in the development of hypophosphatemia.