Introduction : Chronic Kidney Disease (CKD) leads to a gradual loss of kidney function, increasing the risk of cardiovascular complications. Inflammation, mediated by the NF-κB pathway, is a critical factor in CKD progression. Vitamin D deficiency is common in CKD patients and may exacerbate inflammation. This study investigates the effect of Vitamin D3 supplementation on NF-κB levels in CKD-induced rats to explore its potential as a therapeutic intervention.Methods : This experimental study used a post-test only control group design with male white rats (Rattus norvegicus). Rats were divided into three groups: control, CKD-induced, and CKD + Vitamin D3. The study took place in August 2021 at Gadjah Mada University and Sebelas Maret University. NF-κB levels were measured at four-week intervals. Data analysis was performed using SPSS, including ANOVA and post-hoc tests to assess the effects of Vitamin D3 on NF-κB levels.Results : Significant differences in NF-κB levels were observed across the groups. The CKD group showed a steady increase in NF-κB levels, while the CKD + Vitamin D3 group exhibited a significant decrease. By the fourth week, NF-κB levels in the Vitamin D3 group were substantially lower than in the CKD group, indicating the potential anti-inflammatory effects of Vitamin D3 supplementation.Discussion : Vitamin D3 supplementation reduced NF-κB activation in CKD rats, suggesting that it may mitigate inflammation and slow CKD progression. This supports the hypothesis that Vitamin D3 could offer therapeutic benefits in managing CKD-related inflammation and atherosclerosis.Conclusion : Vitamin D3 supplementation significantly reduced NF-κB levels in CKD rats, offering potential for managing CKD-related inflammation. Further research is needed to determine its clinical applicability in human CKD patients. Keywords : Chronic Kidney Disease, NF-κB, Vitamin D3, Inflammation