Amino Acid Supplements in Chronic Kidney Disease
In adults with CKD who are at risk of kidney failure, very low-protein diets (0.3-0.4 g/kg body weight/day) supplemented with essential amino acids or ketoacid analogs (up to 0.6 g/kg body weight/day) should be considered under close supervision, but routine amino acid supplementation is not recommended for most CKD patients. 1, 2
General Protein Intake Recommendations for CKD
- Maintain protein intake at 0.8 g/kg body weight/day in adults with CKD G3-G5 (stages 3-5) 1, 2
- Avoid high protein intake (>1.3 g/kg body weight/day) in adults with CKD at risk of progression 1, 2
- Do not prescribe low- or very low-protein diets in metabolically unstable people with CKD 1, 2
- In older adults with frailty and sarcopenia, consider higher protein and calorie dietary targets 1, 2
Specific Amino Acid Supplement Recommendations
Very Low-Protein Diet with Amino Acid/Ketoacid Supplements
- For adults with CKD who are willing and able, and who are at risk of kidney failure, consider prescribing a very low-protein diet (0.3-0.4 g/kg body weight/day) supplemented with essential amino acids or ketoacid analogs (up to 0.6 g/kg body weight/day) under close supervision 1, 2, 3
- Ketoacid supplements can be converted to their respective amino acids without providing additional nitrogen, reducing the generation of potentially toxic metabolic products 3, 4
- These supplements can also reduce the burden of potassium, phosphorus, and possibly sodium, while still providing calcium 3, 5
Special Considerations for Hospitalized CKD Patients
- CKD patients previously maintained on controlled protein intake ("low protein diet") should not continue this regimen during hospitalization if acute illness is the reason for hospitalization 1
- Protein prescription in hospitalized patients should be guided by the baseline illness that caused hospital admission rather than by the underlying CKD condition 1
- Protein prescription should not be reduced to avoid or delay kidney replacement therapy (KRT) in critically ill patients with AKI, AKI on CKD, or CKD with kidney failure 1
Implementation and Monitoring
- Consult with renal dietitians or accredited nutrition providers to educate people with CKD about dietary adaptations regarding protein, sodium, phosphorus, and potassium intake 1, 2
- Tailor dietary recommendations to individual needs, CKD severity, and comorbid conditions 1, 2
- Monitor nutritional status regularly to avoid protein-energy wasting, which is associated with increased morbidity and mortality 1, 5
- For patients on very low-protein diets with amino acid/ketoacid supplements, monitor serum albumin, transferrin, and nitrogen balance to ensure adequate nutrition 6, 5
Special Population Considerations
Children with CKD
- Do not restrict protein intake in children with CKD due to the risk of growth impairment 1
- Target protein and energy intake in children with CKD G2-G5 should be at the upper end of the normal range for healthy children to promote optimal growth 1
Patients on Dialysis
- In adults with CKD 5D on peritoneal dialysis with protein-energy wasting, amino acid dialysate is not recommended as a general strategy to improve nutritional status 1
- Consider a trial of amino acid dialysate only if nutritional requirements cannot be met with existing oral and enteral intake 1
Common Pitfalls to Avoid
- Implementing protein restriction without proper nutritional counseling and monitoring can lead to malnutrition 2, 5
- Focusing solely on protein restriction without addressing overall diet quality (sodium, phosphorus, potassium) may be counterproductive 2
- Prescribing amino acid supplements with higher protein intakes than the very low-protein diets in which these supplements have been studied has uncertain effectiveness 3