Contemporary Nutritional Strategies in Severe Burn Care: A Systematic Review and Meta-Analysis on Glutamine Supplementation, Vitamin C, and Macronutrient Ratios

Objective To evaluate the clinical efficacy of contemporary nutritional strategies — glutamine, high-dose vitamin C, and macronutrient ratio optimisation — in severe burn care. Background Severe thermal burns trigger profound hypermetabolism, immune dysfunction, and catabolism; the optimal role of specific immunonutrients and carbohydrate-to-fat ratios remains debated. Methods Following PRISMA guidelines, databases and trial registries were searched (January 2021–July 2026) for RCTs and cohort studies of adults with major burns (>15% TBSA); risk of bias was assessed with Cochrane RoB 2.0 and Newcastle-Ottawa scales. Results Nine studies (5 RCTs, 4 cohort/interventional) were included. Glutamine did not significantly reduce infectious morbidity (OR 0.809, 95% CI 0.572–1.145) or length of stay (SMD −0.552, I²=95.2%), a result dominated by RE-ENERGIZE (48.6% weight). In the adequately powered VICTORY RCT (n=238), high-dose IV vitamin C significantly increased 28-day mortality (15.0% vs. 7.6%; RR 1.96, 95% CI 1.32–2.90) versus placebo, prompting early termination for harm. A high-carbohydrate, low-fat protocol in a single retrospective cohort (n=66) was associated with faster wound healing and lower sepsis incidence. Conclusions This review redefines the evidence base for burn nutrition. Routine enteral glutamine monotherapy does not reduce mortality or infectious morbidity; whether combination strategies offer benefit remains a priority for future trials. High-dose intravenous vitamin C should no longer be used for burn resuscitation, given robust randomised evidence of harm. A high-carbohydrate, low-fat strategy shows a genuine, though preliminary, signal for wound healing and sepsis reduction, warranting prospective validation with glycaemic monitoring. These findings support a shift toward phase-specific, evidence-based nutritional protocols in severe burn care.