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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Which of the following is not the action of calcitriol?
assistant
The correct answer is  Calcitriol increases the intestinal absorption of calcium and phosphate. 
In the osteoblasts of bone,  calcitriol stimulates calcium uptake for deposition as calcium phosphate, Thus calcitriol is essential  for bone formation. 
Calcitriol is also involved in minimizing the excretion of calcium and phosphate through the kidney, by decreasing their excretion' and enhancing reabsorption.  
Calcitriol action is similar to steroid hormones. lt binds to a receptor in the cytosol and the complex  acts on DNA to stimulate the synthesis of calcium binding protein.

Reference: Satyanarayana- Biochemistry, 3rd edition, pg-125