Hemodialysis Patients May Benefit from Cholecalciferol Treatment Targeting High Level of 25(OH)D

(1) <i>Background and Objectives</i>: Vitamin D is implicated in the pathogenesis of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD) in hemodialysis (HD) patients, including the development of secondary hyperparathyroidism (SHP). While cholecalciferol supplementation is recommended for vitamin D deficiency correction, its impact on CKD-MBD remains inconsistent. The aim of this observational prospective study was to assess the effect of cholecalciferol in achieving high-normal serum 25-hydroxycholecalciferol (25(OH)D > 75 ng/mL) levels and its impact on CKD-MBD biochemical markers, including 1,25-dihydroxycholecalciferol (1,25(OH)₂D) and parathormone (PTH) in HD patients. The study also evaluated the maintenance dosage required to sustain 25(OH)D levels within the 50-75 ng/mL range. (2) <i>Materials and Methods</i>: A total of 22 HD patients with baseline 25(OH)D levels 30-50 ng/mL received cholecalciferol (70,000 IU/week) to achieve the target serum 25(OH)D > 75 ng/mL. Baseline data on calcium, phosphate, 1-84 PTH, 25(OH)D, and 1,25(OH)₂D serum levels were compared with the data when 25(OH)D > 75 ng/mL was targeted or when the highest 25(OH)D levels were noted. (3) <i>Results</i>: Cholecalciferol significantly improved vitamin D status in HD patients, with 73% reaching the target 25(OH)D level >75 ng/mL in a median time of 7.5 weeks, with a median total dose of 525,000 IU. This was associated with a significant rise in 1,25(OH)₂D, decrease in 1-84 PTH, and no significant effect on calcium and phosphate levels. The median maintenance dose of cholecalciferol was established at 30,000 IU/week. (4) <i>Conclusions</i>: The findings support the use of cholecalciferol targeting high normal 25(OH)D levels to improve biochemical markers of CKD-MBD in HD patients.