Macronutrient and micronutrient requirements and therapeutic effects in critically ill patients with SARS-CoV-2: A narrative review

Abstract

Background: COVID-19 can lead to critical illness and induce hypermetabolism, protein catabolism, and inflammation. These pathological processes may alter energy and protein requirements, and certain micronutrients may attenuate the associated detriments. This narrative review summarizes the macronutrient and micronutrient requirements and therapeutic effects in critically ill patients with SARS-CoV-2.

Methods: We searched four databases for randomized controlled trials (RCTs) and studies that measured macronutrient and micronutrient requirements, published from February 2020 to September 2022.

Results: Ten articles reported on energy and protein requirements, and five articles reported the therapeutic effects of ω-3 (n = 1), group B vitamins (n = 1), and vitamin C (n = 3). Patients' resting energy expenditure gradually increased with time, measuring approximately 20 kcal/kg body weight (BW), 25 kcal/kg BW, and 30 kcal/kg BW for the first, second, and third week onwards, respectively. Patients remained in negative nitrogen balances in the first week, and a protein intake of ≥1.5 g/kg BW may be necessary to achieve nitrogen equilibrium. Preliminary evidence suggests that ω-3 fatty acids may protect against renal and respiratory impairments. The therapeutic effects of group B vitamins and vitamin C cannot be ascertained, although intravenous vitamin C appears promising in reducing mortality and inflammation.

Conclusion: There are no RCTs to guide the optimal dose of energy and protein in critically ill patients with SARS-CoV-2. Additional larger-scale, well-designed RCTs are needed to elucidate the therapeutic effects of ω-3, group B vitamins, and vitamin C.

Keywords: COVID-19; energy; fatty acids; nutrition therapy; protein; vitamins.