FGF23 and hypophosphatemia: Subsequent randomized controlled trials have revealed that the diverse reactions of serum FGF23 and phosphate are highly dependent on the forms of intravenous iron preparation utilized; the administration of ferric carboxymaltose led to FGF23-related hypophosphatemia in approximately 70% of the participants; whereas fermoxytol and ferric derisomaltose led its development in less than 10% of the participants (Emrich et al., 2020; Wolf et al., 2020, Wolf et al., 2018).