Abstract
Objective: To assess the effect of vitamin D supplementation in preventing the formation of kidney stones in patients with secondary hyperparathyroidism, exploring its potential as a preventive treatment.
Methods: A prospective clinical trial was conducted at multiple tertiary care hospitals in Lahore. A total of 180 adult patients with biochemically confirmed secondary hyperparathyroidism were enrolled and allocated into two groups: a vitamin D supplementation group (n = 90) and a control group receiving standard care (n = 90). Patients in the intervention group received oral cholecalciferol with dose adjustments guided by biochemical monitoring. Participants were followed for a mean duration of 18 ± 4 months. The primary outcome was the incidence of kidney stone formation, while secondary outcomes included changes in serum 25-hydroxyvitamin D, parathyroid hormone levels, urinary calcium excretion, and adverse events. Results: Vitamin D supplementation resulted in a significant increase in serum 25-hydroxyvitamin D levels and a marked reduction in parathyroid hormone concentrations. Mean vitamin D levels increased from 14.8 ± 4.2 ng/mL to 33.9 ± 6.8 ng/mL, while parathyroid hormone levels decreased from 312 ± 88 pg/mL to 214 ± 67 pg/mL (p < 0.001). Kidney stone formation occurred in 9 patients (10.0%) in the vitamin D group compared with 18 patients (20.0%) in the control group, representing a significant reduction in stone incidence. A modest increase in urinary calcium excretion was observed in the supplementation group; however, sustained hypercalciuria occurred in fewer than 10% of patients and was managed with dose adjustment. No serious adverse events or vitamin D toxicity were reported.Conclusion: Vitamin D supplementation, when administered with careful biochemical surveillance, was associated with a reduced incidence of kidney stone formation in patients with secondary hyperparathyroidism. The findings supported the safe and effective use of vitamin D as part of comprehensive management strategies for secondary hyperparathyroidism in tertiary care settings, particularly in regions with a high prevalence of vitamin D deficiency.