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The Significance of Vitamin C

Vitamin C is an essential nutrient because as humans we can’t make our own. It is required by our bodies for collagen production and wound healing, healthy gene regulation, iron absorption and its antioxidant properties[1]. Scurvy is a well known result of vitamin C deficiency, but lacking vitamin C has also been associated with cardiovascular disease[2][3], osteoporosis and fracture risk[6][7], low mood[4],[5] and poor immune function[8]. When it comes to our immune system vitamin C plays a 2 part role:

  1. It supports the production and function of immune cells[9]

  2. It helps to protect our immune cells and tissues against oxidative damage created by the inflammatory immune process7[10][11].

It is likely due to these effects, that vitamin C has been shown to shorten the duration and intensity of colds[12], reduce length of hospital stay[13] and benefit cases of sepsis, trauma, major burns and postoperative complications[14][15][16].

At present, without viable treatment options the fears around COVID-19 centre on respiratory failure[17]. As a result of immune reactivity, increased inflammation and oxidative stress, damage to lung tissues can lead to acute respiratory distress syndrome[13] in COVID patients. For this reason the role and potential benefits of antioxidants like vitamin C should be more closely explored. As a water-soluble vitamin, vitamin C is quite safe as excess is excreted through the urine. Typically loose stools would be the first signs of overdosing vitamin C orally, a small price to pay for the benefits of staying C replete. According to the National Institutes of Health:

“Vitamin C has low toxicity and is not believed to cause serious adverse effects at high intakes. The most common complaints are diarrhea, nausea, abdominal cramps, and other gastrointestinal disturbances due to the osmotic effect of unabsorbed vitamin C in the gastrointestinal tract”[18].

Possible contributors to vitamin C deficiency include[19]:

  • Low fruit & vegetable consumption

  • Smoking and/or chronic exposure to second-hand smoke

  • Alcohol and heavy consumption

  • Chronic stress

  • Prolonged infection

  • Major Surgery

  • Poor absorption due to digestive problems

  • Cold exposure

  • Medications[20]: corticosteroids, Aspirin, diuretics and estrogen based birth control

Foods rich in vitamin C include, but are not limited to:

  1. Guava

  2. Kiwi

  3. Bellpeppers

  4. Strawberries

  5. Oranges

  6. Papaya

  7. Broccoli

  8. Tomato

  9. Brussels sprouts

  10. Kale

The possible benefits of vitamin C for COVID-19 have yet to be proven as research continues around the novel virus[21][22], however the known benefits of being vitamin C replete are undeniable and outweighs the minimal costs of regular vitamin C intake.

In health & wellness,



[1] Vitamin C. (2019, July 11). Vitamin C. Retrieved from Linus Pauling Institute website:

[2] Moser, M., & Chun, O. (2016). Vitamin C and Heart Health: A Review Based on Findings from Epidemiologic Studies. International Journal of Molecular Sciences, 17(8), 1328.

[3] Martín-Calvo, N., & Martínez-González, M. Á. (2017). Vitamin C Intake is Inversely Associated with Cardiovascular Mortality in a Cohort of Spanish Graduates: The SUN Project. Nutrients, 9(9).

[4] Gariballa, S. (2014). Poor vitamin C status is associated with increased depression symptoms following acute illness in older people. International Journal for Vitamin and Nutrition Research. Internationale Zeitschrift Fur Vitamin- Und Ernahrungsforschung. Journal International De Vitaminologie Et De Nutrition, 84(1–2), 12–17.

[5] Pullar, J. M., Carr, A. C., Bozonet, S. M., & Vissers, M. C. M. (2018). High Vitamin C Status Is Associated with Elevated Mood in Male Tertiary Students. Antioxidants, 7(7).

[6] Zeng, L.-F., Luo, M.-H., Liang, G.-H., Yang, W.-Y., Xiao, X., Wei, X., … Liu, J. (2020). Can Dietary Intake of Vitamin C-Oriented Foods Reduce the Risk of Osteoporosis, Fracture, and BMD Loss? Systematic Review With Meta-Analyses of Recent Studies. Frontiers in Endocrinology, 10.

[7] Malmir, H., Shab-Bidar, S., & Djafarian, K. (2018). Vitamin C intake in relation to bone mineral density and risk of hip fracture and osteoporosis: a systematic review and meta-analysis of observational studies. British Journal of Nutrition, 119(8), 847–858.

[8] Carr, A. C., & Maggini, S. (2017). Vitamin C and Immune Function. Nutrients, 9(11), 1211.

[9] van Gorkom, G. N. Y., Klein Wolterink, R. G. J., Van Elssen, C. H. M. J., Wieten, L., Germeraad, W. T. V., & Bos, G. M. J. (2018). Influence of Vitamin C on Lymphocytes: An Overview. Antioxidants (Basel, Switzerland), 7(3), 41.

[10] Holmannová, D., Koláčková, M., & Krejsek, J. (2012). [Vitamin C and its physiological role with respect to the components of the immune system]. Vnitrni Lekarstvi, 58(10), 743–749. Retrieved from

[11] Boretti, A., & Banik, B. K. (2020). Intravenous vitamin C for reduction of cytokines storm in acute respiratory distress syndrome. Pharmanutrition, 12, 100190.

[12] Hemilä, H. (2017). Vitamin C and Infections. Nutrients, 9(4), 339.

[13] Hemilä, H., & Chalker, E. (2019). Vitamin C Can Shorten the Length of Stay in the ICU: A Meta-Analysis. Nutrients, 11(4), 708.

[14] Fukushima, R., & Yamazaki, E. (2010). Vitamin C requirement in surgical patients. Current Opinion in Clinical Nutrition and Metabolic Care, 13(6), 669–676.

[15] Spoelstra-de Man, A. M. E., Elbers, P. W. G., & Oudemans-Van Straaten, H. M. (2018). Vitamin C: should we supplement? Current Opinion in Critical Care, 24(4), 248–255.

[16] Oudemans-van Straaten, H. M., Man, A. M. S., & de Waard, M. C. (2014). Vitamin C revisited. Critical Care, 18.

[17] Vincent, J.-L., & Taccone, F. S. (2020). Understanding pathways to death in patients with COVID-19. The Lancet Respiratory Medicine.

[18] Office of Dietary Supplements - Vitamin C. (2016). Retrieved from website:

[19] Vitamin C - Health Encyclopedia - University of Rochester Medical Center. (2019). Retrieved from website:

[20] Complementary and Alternative Medicine - Penn State Hershey Medical Center - Drugs that Deplete: Vitamin C (Ascorbic Acid) - Penn State Hershey Medical Center. (n.d.). Retrieved May 11, 2020, from website:

[21] Carr, A. C. (2020). A new clinical trial to test high-dose vitamin C in patients with COVID-19. Critical Care, 24(1). [22] Cheng, R. Z. (2020). Can early and high intravenous dose of vitamin C prevent and treat coronavirus disease 2019 (COVID-19)? Medicine in Drug Discovery, 100028.

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