The Protective Effect of Serum Levels of Vitamins C, D, and E and IgG and IgM Antibodies in Individuals Vaccinated Against COVID-19 and Experienced Disease Relapse

Background: Despite global control measures aimed at ending the COVID-19 pandemic, the disease continues to pose a threat to public health. In this study, we examined the serum levels of vitamins C, D, and E, as well as IgG and IgM antibodies in individuals who had previously been vaccinated against COVID-19 and subsequently experienced a relapse of the disease. Objectives: The objective of this study was to investigate the correlation between sufficient levels of vitamins E, D, and C, the severity of the disease, and the immunological response in vaccinated patients who have experienced a recurrence of COVID-19. Methods: Given the potential role of vitamins C, D, and E in the management of COVID-19, we conducted a study to examine the serum levels of these vitamins in individuals who had previously been vaccinated against COVID-19 and experienced a disease relapse, characterized by symptoms, such as body pain, shortness of breath, cough, and fever. We compared two groups of hospitalized individuals with varying disease severity to healthy individuals. Additionally, we investigated IgG and IgM antibodies in these patients due to the significance of antibody levels in determining disease severity. Results: Our results revealed significant differences in the levels of vitamins C, D, and E between hospitalized individuals and healthy individuals. Furthermore, a notable disparity in serum IgM and IgG levels was observed based on the severity of the disease. However, no significant difference was detected in the average levels of anti-SARS-CoV-2 immunoglobulins among the different groups, whether they had received the AstraZeneca or Sinopharm vaccines. Conclusions: Vitamins C, D, and E play supportive roles in the immune system, aiding the host's immune response. These findings suggest that maintaining adequate levels of these vitamins may be beneficial in preventing SARS-CoV-2 reinfection and reducing disease severity, particularly in cases where vaccine efficacy is uncertain.