Vitamin D and Bone Health Quiz

Vitamin D Functions and Forms

• Vitamin D's main function is to maintain calcium levels and bone health.

Vitamin D Synthesis and Absorption

• Cholecalciferol (D3) is derived from 7-dehydrocholesterol, a steroid precursor in the skin.
• The primary source of Vitamin D in the diet is fatty fish, fish liver oils, and fortified dairy products.
• Vitamin D is absorbed from the diet through micelles by passive diffusion in the small intestine.
• The primary form of dietary Vitamin D absorbed is Cholecalciferol (D3) and Ergocalciferol (D2).

Vitamin D Activation and Metabolism

• 1,25-dihydroxyvitamin D is the active form of Vitamin D, involved in maintaining calcium levels and bone health.
• The hormone involved in the activation of Vitamin D in the kidneys is Parathyroid Hormone (PTH).

Vitamin D Status and Sources

• Approximately 12% of the population in Ireland has sufficient Vitamin D status.
• Vitamin D is not a significant source of dietary Vitamin D in plant-based foods.
• The two forms of Vitamin D are Cholecalciferol (D3) and Ergocalciferol (D2).
• The chemical structure of Vitamin D is a secosteroid, resembling a steroid molecule with a broken ring.