Calciferol

Question 1

how does Calciferol increase the serum Ca2+

Answer 1

1) Increasing GI absorption of phosphorus and Ca2+,
2) Increasing osteoclastic resorption, and
3) Increasing distal renal tubular reabsorption of Ca2+.
4) Promote intestinal absorption of calcium through binding to the vitamin D receptor in the mucosal cytoplasm of the intestine. Subsequently, Ca2+ is absorbed through formation of a Ca2+-binding protein.

Question 2

what is bioactive vitamin D

Answer 2

a steroid hormone

Question 3

what is bioactive vitamin D for

Answer 3

regulating body levels of Ca2+ and phosphorus, and in mineralization of bone

Question 4

what activates vita in D3

Answer 4

by 25-hydroxylation

Question 5

what catalyses the activation of D3?

Answer 5

the 25-hydroxylase in the liver

Question 6

what happens when The active form of vitamin D3 (calcitriol) binds to the vitamin D receptor

Answer 6

a complex if formed with another intracellular receptor, the retinoid-X receptor, that then function as transcription factors to generally activate gene expression.