Does Vitamin C Boost Immune Function?

Check out this answer from Consensus:

Vitamin C plays a crucial role in enhancing immune function by supporting both innate and adaptive immune responses. It improves the function of neutrophils and T-cells, helps prevent and treat infections, and modulates inflammation, particularly in high-risk groups. Its antioxidant properties and role in gene regulation further contribute to its immune-boosting effects. Therefore, adequate intake of vitamin C is essential for maintaining a healthy immune system.

Vitamin C, also known as ascorbic acid, is a vital nutrient for humans, known for its antioxidant properties and its role as a cofactor in various enzymatic reactions. Its potential to boost immune function has been a subject of extensive research, with studies exploring its effects on different components of the immune system.

Key Insights

• Support for Innate and Adaptive Immunity:
  • Vitamin C enhances various cellular functions of both the innate and adaptive immune systems, including epithelial barrier function, chemotaxis, phagocytosis, and microbial killing by neutrophils1 9 10.
  • It also supports the differentiation and proliferation of B- and T-cells, contributing to a robust adaptive immune response1 4.
• Neutrophil Function:
  • Vitamin C accumulates in neutrophils, enhancing their chemotaxis, phagocytosis, oxidative burst activity, and microbial killing1 2 9.
  • Randomized controlled trials have shown that vitamin C supplementation can improve neutrophil function in various populations, including athletes and patients with myocardial infarction2.
• T-Cell Maturation and Function:
  • Vitamin C is essential for the maturation of T-cells, enhancing their development and function through epigenetic mechanisms such as DNA demethylation4 6.
  • It promotes the proliferation and differentiation of T-lymphocytes, which are crucial for adaptive immunity3 4.
• Impact on Infections and Inflammation:
  • Vitamin C deficiency leads to impaired immunity and increased susceptibility to infections. Supplementation can help prevent and treat respiratory and systemic infections by meeting the increased metabolic demands during infections1 9 10.
  • In high-risk groups such as the elderly, athletes, and those with low plasma vitamin C levels, supplementation has been shown to modulate inflammation and improve immune responses5 7 8.
• Antioxidant and Gene Regulatory Roles:
  • As a potent antioxidant, vitamin C protects immune cells from oxidative stress and supports the redox integrity of cells during the inflammatory response1 9 10.
  • It acts as a cofactor for enzymes involved in gene regulation, affecting cell metabolism, survival pathways, and immune cell function7.

Does Vitamin C boost immune function?

Jens Lykkesfeldt has answered Unlikely

An expert from University of Copenhagen in Pharmacology, Toxicology, Vitamin C

Unlikely. Considerable experimental evidence suggests that vitamin C plays an important role in immune function. So getting too little vitamin C may negatively affect immune function.

Little clinical evidence is available, but some studies suggest that people with low vitamin C status – i.e. those not getting sufficient amounts though their normal diets, or those with extra needs such as smokers, pregnant women, sick individuals – may have increased risk increased risk of infections and perhaps this in fact due to inadequate vitamin C. However, if you do not have vitamin C deficiency/insufficiency, do not smoke, is not sick and you eat a relatively balanced diet, it is highly questionable if taking more vitamin C will boost your immune function any further.

Does Vitamin C boost immune function?

Peter  McCaffery has answered Likely

An expert from University of Aberdeen in Biochemistry

Vitamin C is needed for the immune system. Again comes back to deficiency. Someone deficient in vitamin C will be in a bad way, leading to scurvy. For the healthy individual on a good diet though it will not boost immune function further. The review below is really good and gives a few examples of subgroups (e.g. under high stress), or individuals with other medical conditions where vitamin C may have some benefit (https://www.frontiersin.org/articles/10.3389/fimmu.2020.574029/full)

Does Vitamin C boost immune function?

Carol  Haggans has answered Likely

An expert from National Institutes of Health in Nutrition, Dietetics

Vitamin C plays an important role in immunity, probably because of its antioxidant effects, antimicrobial and antiviral actions, and effects on immune system modulators. Therefore, it’s important to get enough vitamin C for a healthy immune system (75 – 120 mg/day for nonsmoking adults, depending on age, sex, and lifestage; people who smoke need an additional 35 mg/day). However, it’s not clear whether vitamin C supplements boost immunity, and their effects might depend in part on how much vitamin C someone gets from the foods they eat. That is, people who don’t get enough vitamin C might benefit more from vitamin C supplements than those who already obtain sufficient vitamin C.

Does Vitamin C boost immune function?

Anjana Rao has answered Near Certain

An expert from La Jolla Institute For Allergy and Immunology in Immunology, Molecular Biology

We don’t necessarily know about all types of immune cells, so the question is a little oversimplified. However, work from our lab (X Yue et al., Journal of Experimental Medicine 2016) has demonstrated clearly that Vitamin C increases the stability and hence the function of a subtype of T cells known as T regulatory cells, which protect the body from autoimmune diseases such as type I diabetes, systemic lupus erythematosus, rheumatoid arthritis and many others.

Does Vitamin C boost immune function?

Anitra Carr has answered Likely

An expert from University of Otago in Vitamin C

Yes – vitamin C does boost immune function. During infections, the body’s vitamin C levels can become depleted, particularly during severe infections like pneumonia (reviewed in [1]). Vitamin C has a number of functions whereby it can boost immune function (reviewed in [2]). These include supporting the skin and other epithelial barrier functions, to help keep bugs out of the body, by acting as an antioxidant to protect the body from the enhanced inflammation and oxidative stress observed during infections, and by supporting various immune cell functions. White blood cell vitamin C levels drop during infections [3, 4], which may impact on their functions. Supplementation with vitamin C can improve depleted white blood cell levels during respiratory infections, and also improve patient outcomes [4].

References:

1.         Carr AC. Vitamin C in pneumonia and sepsis. In: Chen Q, Vissers M, editors. Vitamin C: New Biochemical and Functional Insights. Oxidative Stress and Disease. Boca Raton, FL CRC Press/Taylor & Francis; 2020. p. 115-35.
2.         Carr AC, Maggini S. Vitamin C and immune function. Nutrients. 2017;9(11):E1211.
3.         Hume R, Weyers E. Changes in leucocyte ascorbic acid during the common cold. Scott Med J. 1973;18(1):3-7.
4.         Hunt C, Chakravorty NK, Annan G, Habibzadeh N, Schorah CJ. The clinical effects of vitamin C supplementation in elderly hospitalised patients with acute respiratory infections. Int J Vitam Nutr Res. 1994;64(3):212-9.

Does Vitamin C boost immune function?

Gerard Bos has answered Uncertain

An expert from Maastricht University Medical Center+ in Cancer, Immunology, Hematology

Possibly, but the evidence is not straightforward. Some randomized trials suggest an effect (elderly patients with pneumonia in a Russian paper) and recent Chinese studies might show the same, though peer reviewed publications have to be awaited.

Several studies are ongoing to see if Vitamin c might be helpful for the immune system, ie after bone-marrow stem cell transplantation or sepsis. However these studies do use high dose I.V. vitamin C and reach plasma levels that can not be realized by oral supplementation probably. Again no convincing data yet.

Does Vitamin C boost immune function?

Margreet Vissers has answered Likely

An expert from University of Otago in Vitamin C, Biochemistry, Cancer Immunology

Yes, it would seem so. Many immune functions are affected by vitamin C. Our white blood cells also have very high vitamin C concentrations, indicating the these cells need it to function properly. low vitamin C levels also decrease your capacity to cope with infections.