hormone
Parathyroid hormone (PTH)
Parathyroid hormone is released by the parathyroid glands and helps regulate calcium and phosphate balance.
Educational draft · Human scientific and editorial review pending. About review status
PTH acts on bone and kidney, and it promotes renal production of calcitriol, which changes intestinal calcium handling.
How it works
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.
Evidence: Established · Source checked 2026-09-05 · Sources: NIH National Library of Medicine: Physiology, Parathyroid
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.