Abstract: Chiscano-Camón et al. Critical Care (2020) 24:522 https://doi.org/10.1186/s13054-020-03249-y RESEARCH LETTER Open Access Vitamin C levels in patients with SARS-CoV2-associated acute respiratory distress syndrome Luis Chiscano-Camón1,2,3, Juan Carlos Ruiz-Rodriguez1,2,3*, Adolf Ruiz-Sanmartin1,2, Oriol Roca1,2,3,4 and Ricard Ferrer1,2,3,4 Vitamin C is an antioxidant with anti-inflammatory and immune-supportive properties. Its levels are decreased in patients with sepsis-related acute respiratory distress syndrome (ARDS). Moreover, a significant number of patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) disease developed ARDS [1]. Therefore, we hypothesized that ARDS coronavirus disease 2019 (COVID-19) patients may present vitamin C deficiency. Plasma vitamin C levels in a population of adult ICU patients COVID-19 who met ARDS criteria according to the Berlin definition [2] were prospectively measured. The study was approved by the local Clinical Research Ethics Committee (PR (AG)270/ 2020). Main characteristics of the population included are presented in Table 1. None of the patients included presented shock or sepsis on admission. Equally, no bacterial co-infection during their ICU course was documented. All patients survived. Vitamin C was determined by high-performance liquid chromatography with photodiode detector (detection limit 1.5 mg/L). Vitamin C reference values in general population used to be above 5 mg/L. Seventeen patients (94.4%) had undetectable vitamin C levels and 1 patient had low levels (2.4 mg/L). To our knowledge, this is the first study to analyze the levels of vitamin C in patients with SARS-CoV-2-associated ARDS. Our study revealed that vitamin C levels are undetectable in more than 90% of the patients included. The mechanisms of this significant reduction in vitamin C are uncertain. We hypothesized that several mechanisms, such as increased metabolic consumption due to the enhanced inflammatory response, glomerular hyperfiltration, dialysis, decreased gastrointestinal absorption, or decreased recycling of dehydroascorbate to ascorbic acid, may be involved. Moreover, vitamin C may have implications for treatment of COVID-19-associated ARDS [3]. Indeed, one preclinical study showed that vitamin C increased resistance to infection caused by coronavirus [4]. Moreover, other clinical studies that included surgical patients and patients with pneumonia showed encouraging results in terms of decreased incidence and severity of lung injury and mortality [5]. * Correspondence: jcruiz@vhebron.net 1 Intensive Care Department, Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, Barcelona 08035, Spain 2 Shock, Organ Dysfunction and Resuscitation Research Group, Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, Barcelona 08035, Spain Full list of author information is available at the end of the article © The Author(s). 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative..