Purpose:To investigate the prevalence of copper, zinc, and vitamin D deficiencies in surgical intensive care unit (SICU) patients and the associations between those deficiencies and clinical outcomes.

Methods:We conducted a retrospective study of 210 patients admitted to the SICU of Asan Medical Center between June 2020 and June 2022. Micronutrient levels were measured within 7 days of SICU admission. Primary outcomes were the mortality rate, length of SICU stay, hospital stay duration, and mechanical ventilation duration.

Results:Copper deficiency was found in 35% (68/193), zinc deficiency in 52% (100/193), and severe vitamin D deficiency in 46% (82/179) of patients. Copper-deficient patients showed a significantly higher mortality rate (25.0% vs. 12.8%, P=0.044), longer hospital stays (57.8±47.0 vs. 45.2±36.6 days, P=0.041), and extended mechanical ventilation duration (26.9±23.3 vs. 18.8±15.7 days, P=0.012). Zinc deficiency was associated with higher C-reactive protein levels (16.2±9.5 vs. 11.5±8.8 mg/dL, P=0.001) and lower prealbumin levels (6.5±2.8 vs. 9.9±5.6 mg/dL, P<0.001). Severe vitamin D deficiency (<10 ng/mL) was not significantly associated with mortality or other clinical outcomes (mortality:<10 ng/mL vs. ≥10 ng/mL, 13% vs. 18%, P=0.583).

Conclusion:Micronutrient deficiencies are prevalent in SICU patients. Copper deficiency significantly correlated with poor clinical outcomes, and zinc deficiency showed a strong association with inflammatory markers. Early assessment and supplementation of micronutrients could be beneficial for critically ill surgical patients.