Fibroblast growth factor 23: the making of a hormone

Fibroblast growth factor 23 (FGF23) modulates serum phosphate and 1α,25-dihydroxyvitamin D3 levels. FGF23 expression is in turn regulated by 1α,25-dihydroxyvitamin D3 and dietary phosphate load, and is strikingly elevated during renal progression. In this issue, Nagano and colleagues report that FGF23 can be modulated by intermittently high dietary phosphate in the presence of compromised renal function