Nitrogen Balance
Difference between nitrogen intake (largely from dietary protein) and nitrogen excretion (urine urea, feces, integument), used to assess whole-body protein status in research and clinical settings.
Adults typically maintain zero balance; positive balance occurs in growth, pregnancy, and recovery; negative balance in starvation, trauma, sepsis, and inadequate intake. Limitations include cumulative measurement errors that overestimate retention, and inability to distinguish tissue compartments. MNHD treats nitrogen balance as foundational to historical protein RDA derivation but supplanted for some applications by indicator amino acid oxidation (IAAO).
How one textbook covers it
Modern Nutrition in Health and Disease, 12th ed. — Ch 1: Proteins and Amino Acids
Adults typically maintain zero balance; positive balance occurs in growth, pregnancy, and recovery; negative balance in starvation, trauma, sepsis, and inadequate intake. Limitations include cumulative measurement errors that overestimate retention, and inability to distinguish tissue compartments. MNHD treats nitrogen balance as foundational to historical protein RDA derivation but supplanted for some applications by indicator amino acid oxidation (IAAO).
Related terms
Cachexia, IAAO, Protein