Vitamin C: new applications for an old favourite

Vitamin C is a favourite in many clinic dispensaries for treating infections and supporting immune health. There is a body of research that started as early as the early 1900s on the use of Vitamin C for the treatment of scurvy, the common cold, pneumonia and tetanus. Since then, there has been a multitude of research done on the vitamin, with many new discoveries made.

It has been observed that Vitamin C levels drop during times of infection1 and in white blood cells, Vitamin C is ten times higher than in plasma which shows a possible role in the immune response.2 It can stimulate T-cells3; and high serum levels of Vitamin C are correlated with neutrophil function, and enhanced antibody and mitogenic responses.1 In animal research, Vitamin C was found to be effective against bacteria, viruses, protozoa and candida.2

The most studied infection in humans is the common cold, with Vitamin C halving the number of colds in physically active people and reducing the duration of a cold. There is research suggesting Vitamin C does not decrease the incidence of the common cold in the general population, but these results may have been dose-dependent.2

Vitamin C supplementation appears to be more effective when the baseline is low. Several studies have found 1 gram of Vitamin C per day in children was effective in reducing the duration of a cold by an average of 6-12% but when the dosage was increased to 2 grams daily the results increased to 26% and 29%. Some research suggests the best dosage for the treatment of colds is 15 grams daily. However, several studies using a dose of 6-8 grams daily found a statistically significant dose-response for the duration of common cold symptoms. This may explain the poor results achieved in studies using 3-4 grams daily. 2

Outside of using Vitamin C for infection and the common cold, there are some exciting new applications being revealed in the research.

Bacterial biofilms

A recent study found Vitamin C to be effective against bacterial biofilm formation. Vitamin C inhibits biofilm development by interrupting quorum sensing and other regulatory mechanisms that support biofilm development. Once the Vitamin C has exposed the bacteria within the biofilm, they are more susceptible to death by Vitamin C-induced oxidative stress. The authors also found that low concentrations of Vitamin C can effectively be used as a pre-treatment in those at risk of developing antibiotic resistance from continued high dose drug administration. The use of the nutrient in this way destabilises the biofilm, allowing the antibacterial compound to access the bacteria.4

Metabolic syndrome and Vitamin C

A 2019 study on Metabolic Syndrome (MetS) found that overnutrition caused an increase in gram-negative bacteria in the gut that contributes to inflammation, impaired gut function and endotoxemia.This environment causes a deficiency of Vitamin C in those with MetS, resulting in a cycle of increasing inflammation and oxidative damage along the gut-liver axis due to low Vitamin C status. The result is increased demand for Vitamin C and E in these patients. Improved Vitamin C status may alleviate endotoxemia and its associated inflammation that may initiate metabolic disorders.5

Vitamin C in stem cell biology and regenerative medicine

Vitamin C is a key regulator of stem cell behaviour and is known to influence pluripotency, self-renewal and differentiation. It impacts the epigenetic signature of the cell and is involved in DNA and histone demethylation by promoting the activity of Iron and alpha-ketoglutarate enzymes. It is known to stimulate the proliferation of mesenchyme derived cells such as osteoblasts, immunological T cells, chondrocytes and hyalocytes. The authors of the review concluded Vitamin C is able to modify the epigene and gene expression as well as the microenvironment of stem cells.3

Vitamin C is an essential nutrient that our bodies are not capable of manufacturing and for those who are deficient may play a crucial role in improving not only immune health but also metabolic health and modifying the epigene and gene expression.


  1. Ml VD, Em B, Thielemans E, Deckx L, Clark J, Aim DS. Oral vitamin C supplements to prevent and treat acute upper respiratory tract infections ( Protocol ). Cochrane Rev. 2019;(3). doi:10.1002/
  2. Hemilä H. Vitamin C and infections. Nutrients. 2017;9(4). doi:10.3390/nu9040339
  3. D’Aniello C, Cermola F, Patriarca EJ, Minchiotti G. Vitamin C in Stem Cell Biology: Impact on Extracellular Matrix Homeostasis and Epigenetics. Stem Cells Int. 2017;2017:1-16. doi:10.1155/2017/8936156
  4. Pandit S, Ravikumar V, Abdel-Haleem AM, et al. Low concentrations of vitamin C reduce the synthesis of extracellular polymers and destabilize bacterial biofilms. Front Microbiol. 2017;8(DEC):1-11. doi:10.3389/fmicb.2017.02599
  5. Traber MG, Buettner GR, Bruno RS. The Relationship Between Vitamin C Status, the GUT-Liver Axis, and Metabolic Syndrome. Redox Biol. 2018;21(December 2018):101091. doi:10.1016/j.redox.2018.101091