FGF23 as a calciotropic hormone

Maintaining mineral metabolism requires several organs and hormones. Fibroblast growth factor 23 (FGF23) is a phosphatonin produced by bone cells that reduces renal production of calcitriol – 1,25(OH) 2 D 3 – and induces phosphaturia. The consequences of a reduction in 1,25(OH) 2 D 3 involve changes in calcium homeostasis. There are several factors that regulate FGF23: phosphorus, vitamin D, and parathyroid hormone (PTH). More recently, several studies have demonstrated that calcium also modulates FGF23 production. In a situation of calcium deficiency, the presence of 1,25(OH) 2 D 3 is necessary to optimize intestinal absorption of calcium, and FGF23 is decreased to avoid a reduction in 1,25(OH) 2 D 3 levels.