Three major organs are involved in the production of the active form of vitamin D. List the organs (in order) where the following steps occur. 7-dehydrocholesterol (provitamin D3) ---------- cholecalciferol (vitamin D3)
Cholecalciferol ---------- calcidiol (25-hydroxy cholecalciferol, 25-OH vitamin D)
Calcidiol ---------- calcitriol (1,25-dihydroxy cholecalciferol, 1,25-OH vitamin D)

Question

Three major organs are involved in the production of the active form of vitamin D. List the organs (in order) where the following steps occur. 7-dehydrocholesterol (provitamin D3) ----------> cholecalciferol (vitamin D3)
Cholecalciferol ----------> calcidiol (25-hydroxy cholecalciferol, 25-OH vitamin D)
Calcidiol ----------> calcitriol (1,25-dihydroxy cholecalciferol, 1,25-OH vitamin D)

Quizplus · Accepted Answer

The correct order of organs involved in the production of the active form of vitamin D is: skin (where 7-dehydrocholesterol is converted to cholecalciferol under UV light), liver (where cholecalciferol is converted to calcidiol), and kidney (where calcidiol is finally converted to calcitriol, the active form of vitamin D).

Three Major Organs Are Involved in the Production of the Active