Calcitriol

Definition

Calcitriol is the active form of vitamin D, crucial for calcium and phosphate metabolism in the body. It plays a key role in maintaining bone health and proper functioning of the immune system.

5 Must Know Facts For Your Next Test

1. Calcitriol enhances intestinal absorption of calcium, which is vital for bone mineralization.
2. It is synthesized in the kidneys from its precursor, calcidiol, under the influence of parathyroid hormone (PTH).
3. Calcitriol also helps regulate levels of phosphorus in the blood by promoting its absorption from food.
4. Deficiency in calcitriol can lead to conditions like rickets in children and osteomalacia in adults.
5. It is used therapeutically to treat conditions such as hypocalcemia, secondary hyperparathyroidism, and certain types of rickets.

Review Questions

• What role does calcitriol play in calcium metabolism?
• How is calcitriol synthesized in the body?
• What are some medical conditions that can be treated with calcitriol?

Related terms

Parathyroid Hormone (PTH): A hormone secreted by the parathyroid glands that regulates serum calcium levels.

Calcidiol: The inactive precursor of calcitriol produced in the liver from vitamin D3.

Osteomalacia: A condition characterized by softened bones due to defective bone mineralization, often caused by a deficiency in vitamin D or its active form, calcitriol.