The body uses amino acids for proteins or nonessential amino acid, for other compounds such as for synthesis of neurotransmitters norepinephrine and epinephrine and melanin, or for energy. The different side chains of the amino acids making …show more content…
Based on the idea that in adults equilibrium is obtained when supplies of essential AAs and total N are adequate for replacement of exogenous losses that occur through the kidney, intestine, sweat, and loss of epithelial cells and for synthesis of tissues such as hair and nails B= I-(U+F+S). Errors in N balance are greater when protein intake is high such factors as energy intake, diet composition and prior nutritional status affect balance and must be considered. The body as a whole may be in balance while some body tissues are in negative balance. An initial negative balance in a subject put on an experimental diet indicates the previous diet was higher in N not that the experimental diet is inadequate. It takes several days to adjust. If energy is below a critical factor then energy not protein will be the limiting factor in N balance rather than protein. If energy and nutrition intakes are adequate N balance is dependent on: Amount and proportion of essential AAs. The Total N intake a person could be in N balance but amino acid imbalance. The Conditions would be associated with zero, positive, and negative Nitrogen balance. Zero N balance: normal, healthy adult and lactating mothers. Positive N balance: growing children and pregnant women. Negative N balance: people who are sick or in trauma and people with kidney