The effects and safety of high dose vitamin D3 in hemodialysis patients.

Background: Different studies have shown that hemodialysis patients require higher doses of Vitamin D3 (VD3) than the general population to achieve satisfactory replenishment. This study aims to assess the safety of such practice and its benefits on some of the parameters of Chronic Kidney Disease- Mineral and Bone Disorder (CKD-MBD).

Methods: A single-center clinical trial assessing the benefits of high dose VD3 in hemodialysis patients. The dose of VD3 (300,000 IU) was administered orally and monthly from April to December 2020 (9 months) at the dialysis unit. The data analyzed were blood levels of calcium, phosphorus, alkaline phosphatase, 25(OH)D, 1,25(OH)2D and intact parathyroid hormone (iPTH) done every three months.

Results: We could recruit a cohort of 23 patients. Blood levels of 25(OH)D increased significantly in 82.6% of the patients to above 30 ng/ml. A similar effect was observed with 1, 25(OH)2D levels. iPTH levels decreased significantly when levels of 25(OH)D exceeded 30ng/ml at the end of the nine months. Vitamin D serum levels were typically measured immediately before the next monthly dose was administered. Blood levels of calcium, phosphorus, and alkaline phosphatase were stable during the study period. No events of hypercalcemia were reported, and no patient discontinued the monthly VD3 supplementation.

Conclusion: Monthly administration of a high dose of VD3 over a long period of nine months in hemodialysis patients was found to be safe and beneficial in VD3 replenishment. It also allowed a significant decrease in iPTH levels. Further studies are warranted to identify the therapeutic target level of 25(OH)D in hemodialysis patients, allowing beneficial effects on iPTH.