nutrients Article Patients with Community Acquired Pneumonia Exhibit Depleted Vitamin C Status and Elevated Oxidative Stress Anitra C. Carr 1, * , Emma Spencer 1 , Liane Dixon 2 and Stephen T. Chambers 3 1 Nutrition in Medicine Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch 8011, New Zealand; emma.spencer@otago.ac.nz 2 Department of Infectious Diseases, Christchurch Hospital, Christchurch 8011, New Zealand; liane.dixon@cdhb.health.nz 3 The Infection Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch 8011, New Zealand; steve.chambers@otago.ac.nz * Correspondence: anitra.carr@otago.ac.nz; Tel.: +643-364-0649 Received: 13 April 2020; Accepted: 1 May 2020; Published: 6 May 2020   Abstract: Pneumonia is a severe lower respiratory tract infection that is a common complication and a major cause of mortality of the vitamin C-deficiency disease scurvy. This suggests an important link between vitamin C status and lower respiratory tract infections. Due to the paucity of information on the vitamin C status of patients with pneumonia, we assessed the vitamin C status of 50 patients with community-acquired pneumonia and compared these with 50 healthy community controls. The pneumonia cohort comprised 44 patients recruited through the Acute Medical Assessment Unit (AMAU) and 6 patients recruited through the Intensive Care Unit (ICU); mean age 68 ± 17 years, 54% male. Clinical, microbiological and hematological parameters were recorded. Blood samples were tested for vitamin C status using HPLC with electrochemical detection and protein carbonyl concentrations, an established marker of oxidative stress, using ELISA. Patients with pneumonia had depleted vitamin C status compared with healthy controls (23 ± 14 μmol/L vs. 56 ± 24 μmol/L, p < 0.001). The more severe patients in the ICU had significantly lower vitamin C status than those recruited through AMAU (11 ± 3 μmol/L vs. 24 ± 14 μmol/L, p = 0.02). The pneumonia cohort comprised 62% with hypovitaminosis C and 22% with deficiency, compared with only 8% hypovitaminosis C and no cases of deficiency in the healthy controls. The pneumonia cohort also exhibited significantly elevated protein carbonyl concentrations compared with the healthy controls (p < 0.001), indicating enhanced oxidative stress in the patients. We were able to collect subsequent samples from 28% of the cohort (mean 2.7 ± 1.7 days; range 1–7 days). These showed no significant differences in vitamin C status or protein carbonyl concentrations compared with baseline values (p = 0.6). Overall, the depleted vitamin C status and elevated oxidative stress observed in the patients with pneumonia indicates an enhanced requirement for the vitamin during their illness. Therefore, these patients would likely benefit from additional vitamin C supplementation to restore their blood and tissue levels to optimal. This may decrease excessive oxidative stress and aid in their recovery. Keywords: vitamin C; ascorbic acid; ascorbate; pneumonia; community acquired pneumonia; oxidative stress; protein carbonyls; hypovitaminosis C; vitamin C deficiency 1. Introduction Pneumonia is a severe lower respiratory tract infection that can be caused by bacterial, fungal and viral pathogens, including the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) [1,2]. Lower respiratory tract infections are the leading cause of morbidity and mortality for communicable Nutrients 2020, 12, 1318; doi:10.3390/nu12051318 www.mdpi.com/journal/nutrients