FGF23 and Hypocalcemia: In situations with elevated PTH and subsequently increased 1,25(OH)2D to cope with hypocalcemia, FGF23 may fine‐tune the balance between bone resorption and intestinal absorption of calcium and phosphate by putting a brake on PTH‐stimulated 1,25(OH)2D production, possibly modulated by extracellular phosphate concentrations.