What would be the nitrogen balance for a patient with a 24-hour urinary nitrogen excretion of 14.3 grams and a protein intake of 102 grams?

What would be the nitrogen balance for a patient with a 24-hour urinary nitrogen excretion of 14.3 grams and a protein intake of 102 grams?

• A. +16.3 grams
• B. −16.3 grams
• C. −2 grams
• D. +2 grams

Answer: (C)

Nitrogen balance reflects whether intake of nitrogen from protein exceeds losses. To compute it, convert protein intake to nitrogen: 102 g protein ÷ 6.25 ≈ 16.32 g nitrogen. Subtract the daily nitrogen losses (urinary excretion) from this: 16.32 g − 14.3 g ≈ 2.02 g. The nitrogen balance is about +2 g, indicating net nitrogen retention. This positive balance suggests the protein intake is sufficient for maintenance or growth given the loss, assuming non-urinary losses are not significantly different from zero in this context.

Nitrogen balance reflects whether intake of nitrogen from protein exceeds losses. To compute it, convert protein intake to nitrogen: 102 g protein ÷ 6.25 ≈ 16.32 g nitrogen. Subtract the daily nitrogen losses (urinary excretion) from this: 16.32 g − 14.3 g ≈ 2.02 g. The nitrogen balance is about +2 g, indicating net nitrogen retention. This positive balance suggests the protein intake is sufficient for maintenance or growth given the loss, assuming non-urinary losses are not significantly different from zero in this context.