Vitamin D in Dialysis Patients - Diagnostic and Therapeutic Management

This study evaluates how best to diagnose and treat vitamin D deficiency in patients with stage 5 chronic kidney disease who are on dialysis. Low vitamin D is very common in dialysis patients and can contribute to bone disease, heart problems, and immune dysfunction. The study aims to find the safest and most effective vitamin D supplementation approach for this group. **You may be eligible if:** - You have stage 5 chronic kidney disease (end-stage kidney disease) and are currently on dialysis - Your vitamin D level (25-hydroxyvitamin D) is below 30 ng/mL (deficient or insufficient) **You may NOT be eligible if:** - You have been on dialysis for less than 3 months - Your parathyroid hormone levels are very high (above 800 pg/mL) and not well controlled - You are already taking calcimimetics or active vitamin D3 medications - You have had a parathyroid gland removal or both kidneys removed - You are on long-term corticosteroid treatment - You have not consented to participate Talk to your doctor to see if this trial is right for you.