Vitamin C deficiency is common in chronic kidney disease and in hemodialysis patients due to malnutrition, malabsorption, restriction of diet rich vitamin C as it rich also in potassium and huge amount of vitamin C loss during hemodialysis. Secondaryhyperparathyroidism is common patients with CKD and is associated with a variety of complications. We found vitamin C deficiency aggravating secondaryhyperparathyroidism in chronic kidney diseases before and after dialysis as binding ofPTH to its receptor depends on vitamin C.Vitamin C deficiency may result in end-organ resistance to PTH. Vitamin C may play acritical role in vitamin D metabolism and vitamin D binding in target tissues. The study shows vitamin C deficiency in patients who undergone renal transplantation however secondary hyperparathyroidism improved. The study showed a relation between vitamin Cdeficiency and hypertension and diabetes as it affect both of them also found a relation between secondary hyperparathyroidism and hypertension