Calcium and Vitamin D Metabolism

The video explains the importance of vitamin D in calcium absorption, detailing how vitamin D is metabolized into its active form, calcitriol, which is crucial for calcium absorption in the intestines. It highlights the need for a healthy liver and kidneys for this process and discusses the role of calcitriol in enhancing calcium uptake. The video also provides recommended dietary allowances for vitamin D and calcium across different age groups.

What is the initial form of Vitamin D absorbed from food or produced in the skin?

• Calbindin

• Calcidiol

• Calcitriol

• Cholecalciferol

Where does the conversion of Vitamin D into its active form begin?

• In the small intestine

• In the bloodstream

• In the liver

• In the kidney

Why is a healthy liver and kidney important for Vitamin D conversion?

• They store Vitamin D

• They convert Vitamin D into calcitriol

• They produce Vitamin D

• They excrete excess Vitamin D

What role does calcitriol play in calcium absorption in the small intestine?

• It excretes calcium

• It stores calcium

• It activates calcium transporters

• It binds calcium directly

Which protein does calcium bind to within the enterocyte?

• Calbindin D

• Retinoid X receptor

• ATP-dependent pump

• Calcitriol receptor

What is the function of the ATP-dependent calcium pump in calcium absorption?

• It binds calcium to calbindin

• It pumps calcium into the bloodstream

• It stores calcium in the cell

• It converts Vitamin D to calcitriol

How does calcitriol affect the expression of calcium transporters?

• It has no effect

• It inhibits their function

• It increases their expression

• It decreases their expression

What is the recommended daily intake of Vitamin D for individuals over 70 years old?

• 800 IU

• 400 IU

• 600 IU

• 1000 IU

What is the recommended daily calcium intake for adults aged 19 to 50 years?

• 700 mg

• 1000 mg

• 1300 mg

• 1500 mg

For females over 71 years, what is the recommended daily calcium intake?

• 1000 mg

• 1200 mg

• 1300 mg

• 1400 mg