Together, our data demonstrate that dietary intake of high phosphorus for 2 weeks does not result in hyperphosphatemia but elevates circulating FGF23, which aids the kidney to appropriately handle the phosphate load from the diet by inducing phosphate excretion (via downregulation of the renal phosphate transporters NaPi2a/c) and reducing phosphate absorption in the intestine (via decrease in 1,25(OH)2D synthesis). Here, FGF23 is linked to hyperphosphatemia.