Active form of vitamin D is
|A||1,25 OH2 Cholecalciferol|
|B||24,25 OH2 Cholecalciferol|
|C||25 OH Cholecalciferol|
Also called as vit D3 I calcitriol, the active form of vitamin D is formed as follows:
The essential feature about the last step occurring in kidney is that this step is stimulated by Parathormone, prolactin.
a. Increasing the synthesis of calbindin, which increases calcium absorption from intestines and calcium reabsorption in kidneys.
b. Increases the activity of osteoclasts, which increases calcium and phosphate levels.