Personalized Low-Protein Diet Combined with Structured Micronutrient Supplementation in Patients with Chronic Kidney Disease: A Retrospective Observational Study

Objective: to evaluate the feasibility, safety, and preliminary effectiveness of an integrated nutritional strategy combining a low-protein diet with structured micronutrient supplementation in patients with advanced CKD. Methods: A retrospective observational study was conducted in routine nephrology practice across two centers between January 2021 and June 2022. Seventeen adults aged 40–85 years with CKD stages III–V were included. Participants followed an individualized low-protein diet emphasizing plant-based foods and received a structured supplementation protocol containing vitamins, minerals, essential amino acids, and omega-3 fatty acids. Primary outcomes were feasibility, adherence, retention, safety, and tolerability. Secondary exploratory outcomes included changes in estimated glomerular filtration rate (eGFR), serum creatinine, and KDIGO stage classification. Results: The retention rate was 94% and the adherence rate was 100%. No serious adverse events or clinically significant electrolyte disturbances were reported. After a mean follow-up of 4.88 months, mean eGFR increased significantly from 43.3 to 59.8 mL/min/1.73 m² (p < 0.001), while serum creatinine decreased significantly from 1.70 to 1.25 mg/dL (p < 0.001). All patients demonstrated directional improvement, and 94.1% improved by at least one KDIGO stage. Conclusions: Integrated nutritional guidelines were feasible, well tolerated, and associated with significant short-term improvements in renal function among patients with advanced CKD. These findings support the need for a randomized controlled trial to confirm efficacy and assess long-term clinical benefits.