What does vitamin c do for the immune system
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The Role of Vitamin C in Immune System Function
Vitamin C and Immune Defense Mechanisms
Vitamin C, also known as ascorbic acid, is a vital micronutrient with multiple roles in the immune system. It acts as a potent antioxidant and a cofactor for various biosynthetic and gene regulatory enzymes, which are crucial for maintaining immune function 18. Vitamin C supports the epithelial barrier function against pathogens and promotes the oxidant scavenging activity of the skin, thereby protecting against environmental oxidative stress 19.
Enhancement of Innate and Adaptive Immunity
Vitamin C is essential for the proper functioning of both the innate and adaptive immune systems. It accumulates in phagocytic cells such as neutrophils, enhancing their chemotaxis, phagocytosis, and microbial killing capabilities 18. Additionally, vitamin C is necessary for the apoptosis and clearance of spent neutrophils from infection sites by macrophages, reducing potential tissue damage 19.
In the adaptive immune system, vitamin C has been shown to enhance the differentiation and proliferation of B- and T-cells, likely due to its gene-regulating effects 17. It also promotes the maturation of T-cells, which is crucial for a robust immune response 7.
Impact on Inflammatory Response and Antiviral Activity
Vitamin C plays a significant role in modulating the inflammatory response. It helps maintain the redox integrity of cells, protecting them against reactive oxygen species generated during the respiratory burst and inflammatory response 8. This is particularly important during infections, where vitamin C levels can rapidly decline due to increased metabolic demands 89.
Moreover, vitamin C has demonstrated antiviral properties, particularly against influenza viruses. It enhances the production of antiviral cytokines such as interferon (IFN)-α/β, which are crucial for the early immune response to viral infections 5. In vitamin C-deficient conditions, the production of these cytokines is impaired, leading to increased viral titers and inflammation 5.
Vitamin C Deficiency and Susceptibility to Infections
A deficiency in vitamin C can lead to impaired immunity and increased susceptibility to infections. This is because vitamin C is crucial for various immune functions, including the production and function of white blood cells 16. Infections, in turn, can further deplete vitamin C levels due to enhanced inflammation and metabolic requirements, creating a vicious cycle of deficiency and susceptibility 19.
Supplementation and Immune Health
Supplementation with vitamin C has been shown to improve various components of the immune system, such as antimicrobial and natural killer cell activities, lymphocyte proliferation, and chemotaxis 8. While a balanced diet that meets the daily intake of vitamin C is generally sufficient for maintaining immune health, supplementation may be beneficial in certain populations, such as the elderly, athletes, and individuals with low plasma vitamin C levels 34.
In conclusion, vitamin C is a critical nutrient for the immune system, supporting both innate and adaptive immune functions, modulating the inflammatory response, and providing antiviral defense. Ensuring adequate intake of vitamin C is essential for maintaining a robust immune system and reducing the risk of infections.
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Most relevant research papers on this topic
Vitamin C and Immune Function
Vitamin C contributes to immune defense by supporting various cellular functions of both the innate and adaptive immune systems, enhancing microbial killing, and preventing and treating respiratory and systemic infections.
Very Rigorous Journal
Highly CitedVitamin C and immune cell function in inflammation and cancer
Low vitamin C levels can negatively impact immune cell function, cell metabolism, and epigenetics, potentially affecting inflammation and cancer.
Highly CitedThe Long History of Vitamin C: From Prevention of the Common Cold to Potential Aid in the Treatment of COVID-19
Vitamin C supplementation may be beneficial for certain groups at high risk of infection, but its effectiveness in reducing respiratory infections remains unclear.
Literature ReviewHighly CitedEffect of vitamin C supplements on cell-mediated immunity in old people.
Vitamin C supplements can enhance T lymphocyte proliferation and tuberculin skin hypersensitivity in elderly individuals, but do not significantly affect serum IgA, IgG, and IgM levels.
RCTHighly CitedVitamin C Is an Essential Factor on the Anti-viral Immune Responses through the Production of Interferon-α/β at the Initial Stage of Influenza A Virus (H3N2) Infection
Vitamin C enhances anti-viral immune responses at the early stage of influenza virus infection by increasing production of interferon-/.
Non-RCT
Animal StudyHighly CitedVitamin C as A Possible Immunity Booster
Vitamin C may enhance immune system function by regulating white blood cell health and gene expression, potentially improving infection prevention and treatment.
Literature ReviewVitamin C promotes maturation of T-cells.
Ascorbic acid plays a crucial role in T-cell maturation and enhances immune function through its role in lymphoid cell-intrinsic development and epigenetic mechanisms.
In Vitro StudyHighly CitedImmune-Enhancing Role of Vitamin C and Zinc and Effect on Clinical Conditions
Vitamin C and zinc supplementation improves immune function and reduces the risk, severity, and duration of infectious diseases, particularly in developing countries.
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