hormone
Parathyroid hormone (PTH)
Parathyroid hormone is released by the parathyroid glands and helps regulate calcium and phosphate balance.
PTH acts on bone and kidney, and it promotes renal production of calcitriol, which changes intestinal calcium handling.
A calcium-regulating signal
Chief cells in the parathyroid glands sense circulating calcium and release PTH when regulation requires it. PTH increases renal calcium reabsorption, changes phosphate handling and stimulates renal 1-alpha-hydroxylase, the enzyme that produces calcitriol.
Related topics
Parathyroid hormone (PTH) stimulates renal production of Calcitriol
PTH increases renal 1-alpha-hydroxylase activity, which produces calcitriol.
Worth knowing
PTH and calcitriol are linked. PTH promotes calcitriol production in the kidney; calcitriol then participates in calcium and phosphate regulation through intestinal and other tissues.
A closer look
Feedback keeps the system moving
Calcium-sensing feedback reduces PTH secretion when circulating calcium rises, coordinating kidney and bone responses.
References
Source-checked local draft.
Human editorial review pending.
- NIH National Library of MedicinePhysiology, ParathyroidChecked 2026-09-05