<prompt> Steroidal prohormone is:Vitamin AVitamin CVitamin DNone of these  <response>: Ans. C. Vitamin DVitamin D is a steroid prohormone. It is represented by steroids that occur in animals, plants and yeast. Active form of the hormone is 1, 25-dihydroxy vitamin D3 1, 25-OH2D3, also termed calcitriol. Calcitriol functions primarily to regulate calcium and phosphorous homeostasis. 