Comparison of nitrogen utilization of two elemental diets in patients with Crohn's disease

Energy, nitrogen absorption, and nitrogen utilization of two commercial elemental diets, Vivonex and Vital, were compared in 10 teenage boys and girls with Crohn's disease. The diets were given in random order as overnight feedings and were the sole source of nutrients for two consecutive periods of 3 weeks each. Urine and stools were collected for 48 h at the end of each 3-week period. Energy absorption was slightly better on Vivonex (p less than 0.05), although 95-100% of energy was absorbed with both formulas. Nitrogen absorption was not different for the two formulas, but nitrogen utilization was significantly better on Vital (28.6 +/- 12.9% versus 9.7 +/- 17.7%, p less than 0.01). This difference may be attributable to the different concentrations of sulfur-containing and aromatic amino acids in the two formulas.