Kidney transplantation restores kidney function through the introduction of a new organ. Key dietary considerations for the pre-transplantation phase, early and late post-transplantation periods, and long-term nutrition management are outlined here ¹.

Nutritional requirements should individually adapted to the individual’s metabolic condition. 

Goals of Nutritional Therapy

• Maintain or improve nutritional status.
• Prevent malnutrition, overweight, or nutrient deficiencies.
• Mitigate steroid therapy side effects through a varied and balanced diet.

Nutritional needs should primarily be met through oral intake. If fortified foods, snacks, or oral supplements provide less than 75% of the required nutrients, enteral nutrition should be introduced. If oral and/or enteral intake still falls short of 75%, complementary parenteral nutrition is indicated. Patients in this group are metabolically and nutritionally diverse and complex, allowing only for general recommendations ².

Pre-Transplantation

The primary objective of pre-transplant nutrition therapy is to correct severe malnutrition, prevent fluid overload, and address electrolyte imbalances. Risk factors for complications, such as uncontrolled diabetes mellitus, obesity, smoking, severe dyslipidemia, and hypertension, should be carefully managed and treated. For overweight patients, a BMI below 35 kg/m² is recommended. Assessments of calcium, phosphate, parathyroid hormone, bone status, calcium salts, and vitamin D levels should be conducted. Adequate micronutrient intake can reduce infection risk, improve wound healing, and preserve muscle mass ^{3, 4}.

During Transplantation

It is critical to avoid both mild and severe fluid overload to prevent retention issues. Strict monitoring of electrolytes, including potassium, phosphate, and magnesium, as well as acid-base balance, is essential. Corticosteroids administered postoperatively increase protein catabolism. Non-diabetic patients frequently experience hyperglycemia, necessitating strict glucose control to reduce the risk of post-transplant diabetes mellitus. Additionally, immunosuppressants may cause hypophosphatemia or hypomagnesemia.

Early Post-Transplantation Phase

Surgical trauma from kidney transplantation is considered mild, with bowel function typically recovering quickly, making artificial nutrition generally unnecessary. Mild trauma, malnutrition, high-dose steroid therapy, and delayed kidney function recovery make transplanted uremic patients susceptible to protein-energy wasting. A high protein intake (approximately 1.3 g/kg body weight) and physical activity can mitigate protein and energy loss, particularly with high doses of corticosteroids ^{3, 5}. Some patients may require hemodialysis due to delayed graft function, with their nutrient needs often resembling those of acute kidney injury patients ⁴.

Late Post-Transplantation Phase

Post-transplant complications vary depending on the underlying disease and may include hypertension, cardiovascular conditions, and associated metabolic disorders. Close monitoring of metabolic developments is necessary, with specific therapeutic measures targeting common complications such as:

• Chronic kidney disease, typically stages 3-4 (KDIGO).
• Impaired glucose tolerance or diabetes mellitus.
• Weight gain, obesity, or metabolic syndrome.
• Persistent hypertension.
• Renal phosphate loss in pre-existing hyperparathyroidism, "Hungry Bone" syndrome, or Mineral Bone Disease.
• Persistent metabolic acidosis.
• Dyslipidemia: Characterized by elevated total and LDL cholesterol levels ³, often caused by steroids, kidney dysfunction, proteinuria, cyclosporin, excess body weight, or an inappropriate diet ⁶.
• Persistent anemia.
• Ongoing protein catabolism.

Nutritional recommendations for kidney transplant patients readmitted due to acute conditions should align with those for acute kidney injury patients (Refer to the Acute Kidney Injury or Chronic Kidney Disease with Acute Illness chapter).

Medications/Supplements

• Avoid food interactions with immunosuppressants (e.g., grapefruit, pomegranate, pomelo, star fruit, St. John's Wort).
• For intravenous cyclosporin, interactions between the solubilizer and lipid metabolism may be possible ⁴.