Learn Glossary biochemistry

Fibroblast Growth Factor 23 (FGF23)

Bone-derived phosphaturic hormone secreted by osteocytes that lowers serum phosphate by inhibiting renal NaPi-IIa/c reabsorption and suppressing renal CYP27B1, thereby reducing calcitriol synthesis.

Also: FGF23

FGF23 acts on the kidney via the FGFR1-Klotho coreceptor complex. It is induced by elevated phosphate and calcitriol and is a master counterregulator of vitamin D. In chronic kidney disease, FGF23 rises early as part of CKD-mineral bone disorder, suppressing calcitriol and contributing to secondary hyperparathyroidism. Elevated FGF23 is independently associated with cardiovascular mortality in CKD.

How one textbook covers it

  • Modern Nutrition in Health and Disease, 12th ed.Ch 8: Phosphorus

    FGF23 acts on the kidney via the FGFR1-Klotho coreceptor complex. It is induced by elevated phosphate and calcitriol and is a master counterregulator of vitamin D. In chronic kidney disease, FGF23 rises early as part of CKD-mineral bone disorder, suppressing calcitriol and contributing to secondary hyperparathyroidism. Elevated FGF23 is independently associated with cardiovascular mortality in CKD.

Related terms

Calcitriol, Klotho, PTH, Phosphate