Which hormone is elevated in vitamin D deficiency?

Which hormone is elevated in vitamin D deficiency?

• A. Calcium
• B. PTH
• C. Calcitonin
• D. Vitamin D

Answer: (B)

Vitamin D deficiency reduces calcium absorption from the gut, which can lower or destabilize serum calcium. In response, the parathyroid glands secrete more parathyroid hormone to restore calcium levels. PTH raises serum calcium by increasing calcium reabsorption in the kidneys, stimulating bone resorption to release calcium, and promoting production of the active form of vitamin D in the kidney (which helps with intestinal calcium absorption). This cascade creates a state of secondary hyperparathyroidism, so parathyroid hormone is elevated. Calcitonin is released with high calcium and would not be elevated here, calcium itself is a mineral, not a hormone, and vitamin D would be low, not elevated.

Vitamin D deficiency reduces calcium absorption from the gut, which can lower or destabilize serum calcium. In response, the parathyroid glands secrete more parathyroid hormone to restore calcium levels. PTH raises serum calcium by increasing calcium reabsorption in the kidneys, stimulating bone resorption to release calcium, and promoting production of the active form of vitamin D in the kidney (which helps with intestinal calcium absorption). This cascade creates a state of secondary hyperparathyroidism, so parathyroid hormone is elevated. Calcitonin is released with high calcium and would not be elevated here, calcium itself is a mineral, not a hormone, and vitamin D would be low, not elevated.