Fibroblast growth factor 23: a hormone that is central to phosphate homeostasis. It is synthesized by osteoblasts and osteoclasts in response to high phosphate intake, hyperphosphataemia, or an increase in serum calcitriol concentration. It inhibits phosphate reabsorption by the proximal tubule of the kidney and stimulates 24-hydroxylase, the enzyme that converts calcitriol and its precursor, 25-hydroxy vitamin D, into inactive metabolites. It may also have a negative effect on parathyroid hormone synthesis.
Subjects: Medicine and Health.