Vitamin C and Immune Function.

Carr Anitra C., et al.
Nutrients, 2017

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.

Keywords

ascorbate; ascorbic acid; immune system; immunity; infection; lymphocytes; microbial killing; neutrophil function; vitamin C.

Conflict of interest statement

S.M. is employed by Bayer Consumer Care Ltd., a manufacturer of multivitamins, and wrote the section on ‘Vitamin C insufficiency conditions’. A.C.C. has received funding, as a Key Opinion Leader, from Bayer Consumer Care Ltd.

Figures

The enzyme cofactor activities of vitamin C

The enzyme cofactor activities of vitamin C. Vitamin C is a cofactor of a family of biosynthetic and gene regulatory monooxygenase and dioxygenase enzymes. These enzymes are involved in the synthesis of collagen, carnitine, catecholamine hormones, e.g., norepinephrine, and amidated peptide hormones, e.g., vasopressin. These enzymes also hydroxylate transcription factors, e.g., hypoxia-inducible factor 1α, and methylated DNA and histones, thus playing a role in gene transcription and epigenetic regulation. ↑ indicates an increase and ↓ indicates a decrease.

Role of vitamin C in phagocyte function

Role of vitamin C in phagocyte function. Vitamin C has been shown to: (a) enhance neutrophil migration in response to chemoattractants (chemotaxis), (b) enhance engulfment (phagocytosis) of microbes, and (c) stimulate reactive oxygen species (ROS) generation and killing of microbes. (d) Vitamin C supports caspase-dependent apoptosis, enhancing uptake and clearance by macrophages, and inhibits necrosis, including NETosis, thus supporting resolution of the inflammatory response and attenuating tissue damage.

PMID:29099763
DOI:10.3390/nu9111211
PMCID (Free PMC Article):PMC5707683
Category:Immune

The best supplements with Ascorbic Acid in Immune category:

Articles similar to "Vitamin C and Immune Function."

  • The role of Ascorbic Acid in Immune: The Effects of Oral Supplements With Sambucus Nigra, Zinc, Tyndallized Lactobacillus Acidophilus (HA122), Arabinogalactans, Vitamin D, Vitamin E and Vitamin C in Otitis Media With Effusion in Children: A Randomized Controlled Trial. (Objective: To evaluate the ability of oral supplements with immune-stimulating molecules (Sambucus nigra, Zinc, Tyndallized Lactobacillus acidophilus (HA122), Arabinogalactans, vitamin D, vitamin E and vitamin C) to reduce the inflammation of the upper airway tract and improve the outcome of otitis media with effusion (OME) in children... OS with immune-stimulating molecules should be considered as a supporting therapy in children affected by recurrent episodes of UAI associated with OME due to their capacity to improve the immune response and reduce the inflammatory phenomena. OS can improve the fibroendoscopic findings by restoring middle ear ventilation, in addition to their ability to reduce inflammation in the middle ear.)
  • The impact of Ascorbic Acid on Immune: Role of Vitamins D, E and C in Immunity and Inflammation. (Inflammatory responses are operationally characterized by pain, redness, heat and swelling at the site of infection and trauma... OS with immune-stimulating molecules should be considered as a supporting therapy in children affected by recurrent episodes of UAI associated with OME due to their capacity to improve the immune response and reduce the inflammatory phenomena. OS can improve the fibroendoscopic findings by restoring middle ear ventilation, in addition to their ability to reduce inflammation in the middle ear.)
  • The significance of Ascorbic Acid for Immune: Immune-enhancing Role of Vitamin C and Zinc and Effect on Clinical Conditions. (Vitamin C concentrations in the plasma and leukocytes rapidly decline during infections and stress... OS with immune-stimulating molecules should be considered as a supporting therapy in children affected by recurrent episodes of UAI associated with OME due to their capacity to improve the immune response and reduce the inflammatory phenomena. OS can improve the fibroendoscopic findings by restoring middle ear ventilation, in addition to their ability to reduce inflammation in the middle ear.)

Previous article

Extra Dose of Vitamin C Based on a Daily Supplementation Shortens the Common Cold: A Meta-Analysis of 9 Randomized Controlled Trials.

Next article

Vitamin C and carotenoids in organic and conventional fruits grown in Brazil.