ABSTRACT
Protein utilization has been estimated by observing the amount of protein and energy needed to create a positive nitrogen balance. Furthermore, some papers have emphasized the role of nitrogen balance to determine nutrient needs during parenteral nutritional therapy. Energy requirements are dependent on a number of factors which include the body surface area derived from height and weight, age and sex. It can be predicted with reasonable accuracy by the Harris-Benedict equation for normal man. The importance of fluid and electrolyte replacement for promoting tissue perfusion and ionic equilibrium is self-evident. In addition, the processes of malnutrition and refeeding are both associated with major changes in electrolyte balance. Magnesium is the most abundant intracellular ion, after potassium. In protein-calorie malnutrition magnesium deficiency has been documented and in surgical patients Freeman found that increasing magnesium intake up to about 15 mmol per day improved nitrogen balance.
