Objective: Safety and intestinal tolerance of an early high-dose enteral administration of antioxidative vitamins, trace elements, and glutamine dipeptides. Design: open intervention trial. Setting: Two university teaching hospitals. Patients: A total of 14 patients requiring jejunal feeding (64 +/- 14 y). Intervention: A measure of 500 ml/day Intestamin(R) (FreseniusKabi: 250 kcal/1.050 kJ, 300 mug selenium, 20 mg zinc, 400 mg chromium, 1500 mg vitamin C, 500 mg vitamin E, 10 mg beta-carotene, 30 g glutamine) for 5 days beginning 6 h after surgery. Parenteral/enteral nutrition was provided to achieve energy target (25 kcal/kg/day). Assessments: Intestinal complaints, plasma nutrients, and glutathione. Results: Only minor signs of nausea, hiccups, flatulence (3/14). Plasma micronutrients ( except beta-carotene) postoperatively decreased and increased to normal on day 5. Extracellular glutamine remained low (preop: 520 +/- 94; d1: 357 +/- 67; d5: 389 +/- 79 mmol/l); total glutathione decreased (d1: 9.4 +/- 3.8; d5: 3.6 +/- 2.5 mumol/l). Conclusion: Study feed is well tolerated and metabolically safe representing a valuable tool for targeted pharmaconutrient supply.