What is the average half-life of parathyroid hormone (PTH)?

The average half-life of parathyroid hormone (PTH) is typically around 10 minutes. This short half-life is significant because it reflects the rapid turnover and regulatory effects that PTH has in the body, particularly in relation to calcium homeostasis. PTH is released from the parathyroid glands and acts to increase serum calcium levels by promoting calcium release from bones, increasing renal tubular reabsorption of calcium, and stimulating the production of active vitamin D, which in turn increases intestinal absorption of calcium.

The brief duration that PTH remains active in circulation underscores the hormone's role in the fine-tuning of calcium levels, allowing for quick adjustments in response to changing calcium requirements. This adaptive response is essential for maintaining overall metabolic homeostasis and preventing both hypocalcemia and hypercalcemia.

Other options suggest half-lives significantly longer or shorter than 10 minutes, which do not align with the physiological properties of PTH. Understanding the half-life helps clinicians gauge the timing of PTH-related interventions and the dynamics of calcium regulation in patients.