Calcium Homeostasis
Hormonal Regulation of Calcium, Phosphate and Bone
Calcium Homeostasis
Calcium homeostasis maintains extracellular ionized calcium within a tightly regulated physiological range through interactions among intestine, kidney and bone. PTH and vitamin D-related signals are central regulators.
Three organs in communication
Calcium and phosphate regulation coordinates intestine, kidney and bone through PTH, vitamin D-related signals and FGF23. Ionized calcium, renal function and tissue responsiveness influence the pattern. Serum concentration alone does not measure skeletal mineral stores.
Interpreting the mechanism
A stable serum concentration can be maintained despite changes in skeletal stores. Total calcium additionally depends on protein binding and should be distinguished from ionized calcium.
Bone under load
Mechanical loading supplies local signals that interact with endocrine state, adequate energy and nutrient availability. A circulating bone marker can reflect several skeletal sites and does not independently prove stronger bone or predict fracture risk.
Home
Academy
Site Map