Prevalence and natural history of vitamin C deficiency in patients with cirrhosis: A prospective cohort study

ABSTRACT

Background and Aim: Liver cirrhosis is a serious medical condition associated with high morbidity and mortality, and it represents the fifth leading cause of death in adult patients. Malnutrition is a commonly recognized comorbidity in the population with cirrhosis and is associated with a poor prognosis. Ascorbic acid is a water-soluble vitamin present in most plant foods. Dietary deficiency leads to scurvy and may impair liver functions, such as the conversion of cholesterol to bile acids. Vitamin C deficiency (VCD) has traditionally been considered very uncommon in developed countries. However, recent studies indicate a significant prevalence in multiple subgroups, including patients presenting with pneumonia, coronavirus disease 2019 (COVID-19), and upper gastrointestinal bleeding. The prevalence of VCD in the population with cirrhosis remains poorly studied. The aim of this study was to investigate the prevalence of VCD in hospitalized patients with liver cirrhosis and the association between VCD and clinical outcomes. Methods: Patients with liver cirrhosis admitted to three Victorian metropolitan hospitals were prospectively recruited over a 4-month period (January to April 2021). Fasting vitamin C levels were obtained on admission. Baseline demographic data and clinical outcomes were recorded. The primary outcome was the prevalence of VCD, defined as a vitamin C level < 23 mcmol/L, with severe deficiency defined as <12 mcmol/L. Secondary outcomes included mortality, intensive care unit (ICU) admission, and hospital length of stay (LOS). Patients were risk stratified using the Model for End-Stage Liver Disease (MELD) score. Results: A total of 48 patients were included. The median patient age was 59 years (IQR, 50-69), 60% were male, and the median MELD score was 19 (IQR, 14-25). The most common etiologies of cirrhosis were alcohol related (60%), non-alcoholic fatty liver disease (NAFLD) (25%), and hepatitis B (19%). Most patients (83.3%) were admitted with complications of decompensated liver disease, most often ascites (47.9%), hepatic encephalopathy (33.3%), and upper gastrointestinal bleeding (27.1%). Mean vitamin C level on admission was 38 ± 12 mcmol/L. VCD was present in 18 patients (37.5%), with severe deficiency noted in eight (16.7%). VCD was most common in patients with NAFLD (42%), followed by those with hepatitis B (34%) and alcohol-related cirrhosis (31%), although no statistically significant difference in prevalence was found between etiologies of cirrhosis. No significant associations were found between VCD and MELD score, albumin levels, or the nature of the decompensating event. In terms of patient outcomes, inpatient mortality was 6.3%, 16.7% of patients required ICU admission, and the median LOS was 10 days (IQR, 6-16). No significant differences in mortality, ICU admission, or LOS stay were noted between patients with and without VCD, although this may be a result of type II error. Conclusion: VCD is prevalent in hospitalized patients with cirrhosis, with 37.5% noted to have VCD and 16.7% having severe deficiency. Further studies are required to assess the clinical significance of VCD deficiency in cirrhotic patients and the impacts of vitamin C replacement.