Question

Assertion (A): Calcitriol accelerates bone formation.

Reason (R): Calcitriol is the active form of cholecalciferol. It promotes absorption of Ca²+ and phosphorus in the small intestine.

Select the most appropriate answer from the options given below:

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not the correct explanation of A.

(c) A is true but R is false.

(d) if both A and R are false.

Answer 1

Correct option is (a)

Explanation of 'A' & 'R' :- Vitamin D is synthesized in skin epidermis from cholesterol derived compounds in the presence of sunlight. Vitamin D exists in two forms: calciferol or D₂ and cholecalciferol or D3. Cholecalciferol is more important. It circulates in the blood. Calcitriol is active form of D3. It increases the absorption of calcium and phosphorus from chyme in the small intestine and accelerates bone formation.

Result: Hence, it is proved that both 'A' and 'R' are true and as 'R' is the correct explanation of 'A', so the answer is option (a).