FGF23 and hypophosphatemia: Currently, there are no FDA-approved treatments specific for FD, and the mainstays of therapy are to control pain; ensure that abnormalities in mineral metabolism such as calcium, vitamin D, and phosphorus are corrected; and to prevent skeletal and extra-skeletal disease complications that may impact FD bone growth, including acromegaly or IGF-1 excess, hyperthyroidism, and FGF23-mediated hypophosphatemia.