The Effect of Vitamin C on Parathyroid Hormone in Patients on Hemodialysis With Secondary Hyperparathyroidism: A Double Blind, Placebo-Controlled Study

Background: secondary hyperparathyroidism (shpt) is a prevalent disorder in patients with chronic kidney disease. it is proffered that there is a contradictory relation between serum level of vitamin c and parathyroid hormone (pth) in hemodialysis patients with secondary hyperparathyroidism. objectives: the goal of this study was to assess the effects of the supplemental vitamin c on parathyroid hormone among hemodialysis patients with secondary hyperparathyroidism. patients and methods: this randomized, placebo-controlled, double-blind and parallel-group trial was conducted on 82 hemodialysis patients with serum levels of pth more than 200 pg/ml. in intervention group, 250 mg vitamin c was injected three times a week for 8 weeks in a row immediately at the end of each dialysis session via the intravenous route. in the control group, same term of placebo saline was injected. results: the mean of serum pth was 699.81 (± 318.8) and 596.03 (± 410.7) pg/ml in intervention and control groups respectively at baseline (reference range, 6 to 66 pg/ml), and at the end of study it changed to 441.4 and 424.6 in these groups. the values of serum calcium and phosphate did not significantly change during the study (8.4 ± 0.6 mg/dl versus 8.1 ± 0.8 mg/dl, p = 0.39; 5.89 ± 1.7 mg/dl versus 5.9 ± 1.9 mg/dl, p = 0.08, respectively). conclusions: this study finding does not warranted therapeutic effect of vitamin c on secondary hyperparathyroidism.