Serum marker of rickets is

Amongst the given options, alkaline phosphatase is best because it is raised in all type of rickets. The primary (Basic) investigations in a child of rickets are :- Serum calcium Serum phosphorus Alkaline phosphatase If the patient does not respond to calcium and Vit D therapy, secondary investigations are done:- Vit D level Serum PTH Urinary calcium and phosphorus.