PTH is an 84 amino acid peptide hormone with receptors widely expressed in bone on cells of osteoblast lineage and in kidney proximal and distal tubule cells. While the major physiological regulator of PTH secretion is the ionized calcium level through interaction with the calcium sensing receptor, PTH secretion is also modulated by serum phosphate, FGF23, and 1,25-dihydroxyvitamin D3 (Krajisnik et al. 2007; Nissenson and Juppner, 2013). PTH has ostensibly conflicting effects on phosphate homeostasis. Through bone breakdown and enhanced gastrointestinal absorption of phosphate mediated by PTH-stimulated vitamin D production, more phosphate