What is the role of parathyroid hormone?

Parathyroid hormone (PTH) plays a vital role in regulating calcium metabolism within the body. It is secreted by the parathyroid glands in response to low levels of calcium in the blood. PTH functions primarily by increasing calcium concentrations in the bloodstream through several mechanisms.

Firstly, it stimulates the release of calcium from bones, where calcium is stored, into the bloodstream. Secondly, it enhances the reabsorption of calcium in the kidneys, reducing the amount excreted in urine. Lastly, PTH promotes the activation of vitamin D in the kidneys, which in turn increases intestinal absorption of calcium from food.

These actions work together to maintain calcium homeostasis, which is crucial for various physiological processes, including nerve conduction, muscle contraction, and blood clotting. The regulation of calcium levels is essential for overall health, making PTH a key hormone in maintaining bone health and metabolic functions related to calcium.