Podcast
Questions and Answers
What is the active form of vitamin D that increases calcium absorption in the intestine?
What is the active form of vitamin D that increases calcium absorption in the intestine?
What hormone is primarily responsible for increasing the concentration of calcium in the blood?
What hormone is primarily responsible for increasing the concentration of calcium in the blood?
Which organ converts vitamin D3 into 25-hydroxycholecalciferol?
Which organ converts vitamin D3 into 25-hydroxycholecalciferol?
What triggers the secretion of calcitonin?
What triggers the secretion of calcitonin?
Signup and view all the answers
How does calcitonin affect the actions of parathyroid hormone (PTH)?
How does calcitonin affect the actions of parathyroid hormone (PTH)?
Signup and view all the answers
Study Notes
Vitamin D3 Metabolism
- Vitamin D3 (cholecalciferol) is obtained through diet or sun exposure.
- The liver converts vitamin D3 to 25-hydroxycholecalciferol (25-OH-D3), an inactive form.
- The kidney hydroxylates 25-OH-D3 to 1,25-dihydroxycholecalciferol (1,25-[OH]2-D3), the active form.
Vitamin D3 Function
- The active form of vitamin D increases calcium (Ca2+) absorption in the intestines.
- It enhances the effects of parathyroid hormone (PTH) on bone resorption.
Calcitonin
- Calcitonin is secreted by medullary cells in the thyroid gland.
- Its secretion is triggered by elevated blood calcium (Ca2+) levels.
- Calcitonin lowers blood calcium by inhibiting PTH and vitamin D.
- Calcitonin is not typically secreted during normal calcium regulation.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz explores the metabolism and physiological functions of vitamin D3, including its conversion processes in the liver and kidneys. It also covers the role of calcitonin in calcium regulation and its interactions with parathyroid hormone. Test your knowledge on these essential topics for understanding calcium homeostasis!
