FGF23 and anemia (phenotype): Since circulating FGF23 is increased by anemia (Farrow et al., 2011; Imel et al., 2011; Nam et al., 2018) and lowered by iron repletion (Imel et al., 2020), in our experiments, a targeted deletion of FGF23 from osteoblasts/osteocytes was used in concert with FC treatment to separate FGF23‐ versus FC‐driven effects.