Alerts its conversion from Vit D3,calcitriol exerts its effects on the body binding to and activating Vit d receptors(VDRs),which are located in the nuclei of target cells.Once activated,VDRs can function as transcription factors that bind to cellular DNA nad control gene expression,ultimately triggering a biological response.
Treatment or prevention of Vitamin D deficiency
Hyperphosphataemia or hypercalcaemia.Associated effects of hypercalcaemia anclude hypercalciuria,ectopic calcification and renal &CV damage