<prompt> Least useful anti-rachitic:1, 25-hydroxy cholecalciferol calcitriolCholecalciferol25-hydroxy cholecalciferolCalcium  <response>: Ans: B, or D Cholecalciferol or. Calcium Ref: Nelsons Textbook of Pediatrics. 19th Edition and CRC Desk Reference for Nutrition, Second Edition, By Carolyn D. BerdanierExplanation:Sorry, I am not sure of the answer since I could not find the source or references for this question. Nutrients that are required for normal bone growth and developement. Vitamin C. Vitamin D and minerals Calcium, phosphorous, magnesium, manganese, pottassium . These nutrients are called Antirachitic because they prevent the development of rickets. Ref: CRC DeskVitamin D Production 