Background: Chronic Kidney Disease (CKD) is a progressive global health issue marked by impaired kidney function and metabolic disturbances. A key complication of CKD is the disruption of calcium and vitamin D balance. Declining kidney function limits the activation of vitamin D, causing hypocalcemia and related complications. Chronic Kidney Disease–Mineral and Bone Disorder (CKD-MBD) commonly arises in CKD, characterized by abnormal mineral metabolism, bone turnover, and vascular calcification, significantly increasing risks of cardiovascular disease and mortality. Recently, plant-based therapies like Moringa oleifera, rich in polyphenols and flavonoids with antioxidant and anti-inflammatory effects, have gained attention for their potential to improve calcium regulation. This study evaluated the effect of vitamin D and the ethyl acetate fraction of Moringa oleifera leaves on serum calcium levels in a CKD rat model.Methods: This experimental study involved 25 male white rats (Rattus norvegicus) divided into five groups (n=5 per group): negative control (normal/NC), positive control (CKD-induced/PC), and three CKD-induced treatment groups (P1, P2, P3). P1 received vitamin D (72 IU/200g/day), P2 received Moringa oleifera extract (20 mg/200g/day), and P3 received both treatments. CKD was induced via unilateral ureteral obstruction (UUO), followed by 10 days of induction and 20 days of treatment. Serum calcium was measured using spectrophotometry (CPC method). Statistical analysis determined differences among groups and the impact of treatments.Results: CKD induction significantly reduced serum calcium levels compared to normal controls. Treatment with vitamin D moderately increased calcium levels, while Moringa oleifera extract alone led to a slightly higher increase. The combination treatment showed the greatest improvement, with calcium levels nearing normal values. All treatment groups had significantly higher calcium levels than the untreated CKD group, with the combined therapy being the most effective.Conclusion: Vitamin D and Moringa oleifera extract effectively improved serum calcium levels in CKD rats. Their combination produced the strongest effect, suggesting a synergistic benefit. This supports the potential integration of conventional and plant-based therapies for managing calcium imbalance in CKD-MBD Keywords: Moringa oleifera, CKD-MBD, Calcium, Vitamin D