Secondary hyperparathyroidism(SHPT) describes a complex alteration in bone and mineral metabolism that occurs as a direct result of CKD. SHPT causes primarily cardiovascular calcification and is directly correlated to increase in morbidity and mortality. Identifying patients at risk and evaluating for SHPT is important because early intervention slows or arrests the progression of bone and cardiac disease in CKD patients. The aim is to evaluate the variation between iPTH and vitamin–D in various stages of CKD. A total of 123 CKD patients which are divided into stage III (n=19), stage IV ( n=27), stage V( n=77) are included in the study. Serum urea, creatinine, albumin, iPTH, 25(OH) D3, calcium and phosphorus are estimated. eGFR calculated by MDRD 6–variable equation. Pearson‘s correlation and ANOVA test are used to assess the relation between the parameters. In CKD values of serum iPTH levels are

higher in stage V compared to other stages, Vit D levels are sufficient in all stages. Statistical significant difference is found with iPTH and phosphorus among different stages of CKD. iPTH (r=–0.33), phosphorus(r=–0.28) are negatively correlated and 25(OH)D3(r=0.035) positively correlated with eGFR. Statistically significant correlation was found between PTH and eGFR with p–value 0.02. Our study shows importance of the determination of iPTH and phosphorus for early detection of SHPT. iPTH level are increased earlier than other bone markers. So early screening of CKD patients with serum iPTH levels helps in early detection and intervention of SHPT which reduces considerable mortality and morbidity.