PTH and hyperphosphatemia: Thus, the main function of FGF23 seems to be the protection of the organism against the deleterious effects of hyperphosphatemia by inhibiting the sodium-dependent phosphate cotransporters in the kidney, decreasing intestinal absorption through the suppression of renal synthesis of 1,25(OH)2D and decreasing bone reabsorption by inhibiting PTH synthesis and release [2,3,8,9,10].