Vitamin C and Immune Function

Abstract

Vitamin C is an essential micronutrient for humans, with pleiotropic functions related to its ability to donate electrons. It is a potent antioxidant and a cofactor for a family of biosynthetic and gene regulatory enzymes. Vitamin C contributes to immune defense by supporting various cellular functions of both the innate and adaptive immune system. Vitamin C supports epithelial barrier function against pathogens and promotes the oxidant scavenging activity of the skin, thereby potentially protecting against environmental oxidative stress. Vitamin C accumulates in phagocytic cells, such as neutrophils, and can enhance chemotaxis, phagocytosis, generation of reactive oxygen species, and ultimately microbial killing. It is also needed for apoptosis and clearance of the spent neutrophils from sites of infection by macrophages, thereby decreasing necrosis/NETosis and potential tissue damage. The role of vitamin C in lymphocytes is less clear, but it has been shown to enhance differentiation and proliferation of B- and T-cells, likely due to its gene regulating effects. Vitamin C deficiency results in impaired immunity and higher susceptibility to infections. In turn, infections significantly impact on vitamin C levels due to enhanced inflammation and metabolic requirements. Furthermore, supplementation with vitamin C appears to be able to both prevent and treat respiratory and systemic infections. Prophylactic prevention of infection requires dietary vitamin C intakes that provide at least adequate, if not saturating plasma levels (i.e., 100–200 mg/day), which optimize cell and tissue levels. In contrast, treatment of established infections requires significantly higher (gram) doses of the vitamin to compensate for the increased inflammatory response and metabolic demand.

Reduced Plasma Ascorbic Acid Levels in Recipients of Myeloablative Conditioning & Hematopoietic Cell Transplantation

“…This phenomenon may be of critical importance in immune reconstitution following HCT. 10 While AA has a significant role in immune function, 32 it has several well-characterized effects on T cells, (e.g., diminish apoptosis 33 ) as well as its crucial impact on the development of double positive and single positive, T cell receptorrearranged, T cells in feeder-free cell culture systems. 34 In particular, the effects on CD8 and ZAP-70 as well as IL-17 expression appear to be mediated via chromatin methylation through the Jomanji C domain enzyme that employs ascorbate as a cofactor for promoting histone demethylation.…”

Intravenous vitamin C for reduction of cytokines storm in acute respiratory distress syndrome

“…The immunomodulatory activities of Vit-C were responsible for this effect. In general, Ascorbic acid is concentrated in leucocytes, lymphocytes, and macrophages [93,94]. Chemotaxis was improved by Vit-C [95][96][97].…”

Dos terapias conocidas podrían ser efectivas como adyuvantes en el paciente crítico infectado por COVID-19

“…La vitamina C tiene efectos inmunoestimulantes, propiedades antioxidantes, antiinflamatorias, antivirales y posibles efectos antimutagénicos 3,4 . Se ha demostrado que la vitamina C mejora la quimiotaxis de neutrófilos, la fagocitosis y, por lo tanto, el aclaramiento microbiano 5,6 . Además, promueve la proliferación de células T y células natural killer que modulan sus funciones 7 .…”

“…El ozono reacciona rápidamente con las biomoléculas que poseen este doble enlace y causa una rápida reacción de oxidación, con la consiguiente formación de moléculas secundarias, que son las causantes de su acción +Model REDAR-1138; No. of Pages 8 6 A. Hernández et al…”