What are the recommended daily intake levels of sodium and protein for individuals with Chronic Kidney Disease (CKD)?

Sodium and Protein Recommendations in Chronic Kidney Disease

For adults with CKD stages 3-5, maintain protein intake at 0.8 g/kg body weight per day and restrict sodium to less than 2 g per day (equivalent to less than 5 g of salt per day). 1

Protein Intake Guidelines

Standard Recommendations for Adults

• Maintain 0.8 g/kg body weight/day for adults with CKD G3-G5, which represents the recommended daily allowance 1
• Avoid high protein intake exceeding 1.3 g/kg/day, as this has been associated with increased albuminuria, more rapid kidney function loss, and cardiovascular mortality 1
• Do not reduce protein below 0.8 g/kg/day, as this does not alter blood glucose levels, cardiovascular risk, or GFR decline 1

Very Low-Protein Diets (Specialized Approach)

• For adults at high risk of kidney failure who are willing and able, consider prescribing 0.3-0.4 g/kg/day supplemented with essential amino acids or ketoacid analogs (up to 0.6 g/kg/day) under close supervision 1
• Never prescribe low or very low-protein diets in metabolically unstable patients 1

Special Populations Requiring Higher Protein

• Older adults with frailty or sarcopenia should receive higher protein and calorie targets to prevent muscle wasting and maintain functional status 1, 2
• Children with CKD should not have protein restriction due to risk of growth impairment; target protein intake should be at the upper end of normal range for healthy children 1
• Dialysis patients require higher protein intake since protein-energy wasting is a major concern 1

Sodium Intake Guidelines

Standard Recommendations

• Restrict sodium to less than 2 g per day (or <90 mmol/day, or <5 g sodium chloride/day) for people with CKD 1, 3
• This target is particularly important for controlling blood pressure and reducing cardiovascular risk 1
• The American Diabetes Association recommends sodium restriction to <2,300 mg/day, which is slightly less restrictive but still within the same range 1

Clinical Context for Sodium Restriction

Sodium restriction becomes especially critical for individuals with reduced eGFR, as urinary excretion of sodium may be impaired 1. Research demonstrates that increased sodium intake correlates with greater use of antihypertensive medications to achieve comparable blood pressure control 4, and short-term sodium restriction significantly reduces blood pressure, proteinuria, and fluid volume markers 5.

Important Exception

• Do not restrict sodium in patients with sodium-wasting nephropathy, as these patients require sodium supplementation rather than restriction 1, 3

Pediatric Considerations

• Follow age-based Recommended Daily Intake for children with CKD who have blood pressure >90th percentile for age, sex, and height 1
• Infants on peritoneal dialysis may require sodium supplementation due to substantial sodium losses 1

Implementation Strategy

Dietary Counseling Approach

• Use renal dietitians or accredited nutrition providers to educate patients about dietary adaptations regarding sodium, phosphorus, potassium, and protein intake, tailored to individual needs and CKD severity 1, 3
• Emphasize plant-based foods over animal-based foods and minimize ultraprocessed foods 1, 2

Monitoring Requirements

The majority (75%) of dietary sodium comes from salt added by manufacturers during food processing, not from salt added at the table 1. Therefore, effective sodium restriction requires:

• Replacing processed and canned foods with fresh foods 1
• Reading food labels to identify lower sodium options 1
• Understanding that one teaspoon of salt contains approximately 2,300 mg of sodium 1

Common Pitfalls to Avoid

Overrestricting protein in frail older adults can lead to sarcopenia and functional decline 2. When frailty or sarcopenia is present, protein intake should be increased above the standard 0.8 g/kg/day recommendation, accompanied by higher calorie targets 2.

Failing to individualize sodium recommendations based on comorbid conditions, medication use (particularly potassium-sparing medications), blood pressure, and laboratory data can lead to adverse outcomes 1.

Prescribing low-protein diets without proper supervision or in metabolically unstable patients can result in malnutrition 1.

Integration with Other CKD Management

Dietary sodium and protein modifications work synergistically with other interventions including blood pressure control (target systolic BP <120 mmHg when tolerated), renin-angiotensin system inhibition for patients with albuminuria, and physical activity (at least 150 minutes per week of moderate-intensity exercise) 1.