Research Blog

April 18, 2020

COVID-19 & Vitamin C Deficiency

Behind every bad disease… is there a good nutrient missing? part 2 - Vitamin c

Dr. Dicken Weatherby & Beth Ellen DiLuglio

The global coronavirus COVID-19 pandemic has mobilized essential healthcare workers to fight the virus on the frontlines. Unfortunately, as of yet there is no definitive curative treatment. These 2 research blog posts are summaries of two published articles exploring the relationship between deficiencies of essential nutrients and immune compromise.

In part 1, we discussed vitamin D deficiency as it relates to immunity. In part 2 will take a look at Vitamin C.

Vitamin C

Vitamin C in immunity and beyond.

The article “A new clinical trial to test high-dose vitamin C in patients with COVID-19” published online April 7, 2020 in Critical Care “introduces” a topic that may be new news to some and old news to others (Carr 2020). Intravenous vitamin C has been used for decades in a variety of settings even though its use was seen as “outside the mainstream.” Streams, main or otherwise, meander all the time. Fortunately, the tide is turning regarding the use of nutrition to restore balance in times of physiological crisis.

The new 2020 randomized controlled trial provides vitamin C intravenously in gram doses to compensate for significantly increased needs due to infection. The protocol will provide 24,000 milligrams of vitamin C per day for seven days in severe COVID-19 patients. Outcomes to be assessed include organ failure scores; ICU length of stay; need for mechanical ventilation and vasopressor drugs; and 28-day mortality. Researchers intend to have results by September 2020, in what we hopefully can call a “post-COVID-19” world.

Vitamin C… what does it do for us?

Vitamin C, also known as ascorbic acid for its ability to resolve scurvy, performs a number of crucial functions in the human body. While most mammals produce their own vitamin C (~50 mg/kg/day under normal circumstances), humans are unable to and must obtain vitamin C from the diet. Unfortunately, humans only ingest ~1 mg/kg/day, falling woefully short of what we need as mammals.

Saturation of plasma levels may be reached with a ~400 mg/day intake of vitamin C and can enhance infection prophylaxis. However, requirements increase with immune challenge, pollution (including smoking), stress, and severity of established infection. A reasonable level of baseline supplementation may be the 50 mg/kg/day that our mammal friends produce. Note that some individuals must restrict vitamin C supplementation including those with hemochromatosis, glucose-6-phospate dehydrogenase (G6PD) deficiency, and those who form oxalate-based kidney stones. Since there can be limited absorption of orally administered vitamin C, intravenous doses may be required in severe infection.

Prolonged deficiency of vitamin C results in classic signs of scurvy including bleeding gums, bruising, and impaired immunity, and poor wound healing due to compromised collagen and connective tissue. However, insufficiency of vitamin C may also manifest as fatigue, lethargy, myalgia, swollen joints, pedal edema, mucosal changes, depression, and mood changes.

Immune functions and benefits of vitamin C include:

  • Antioxidant activity, free radical scavenging, cell and tissue protection
  • Collagen production and connective tissue maintenance
  • Epithelial barrier support
  • Enhancement of chemotaxis, phagocytosis, and microbial killing
  • Enhancement of B- and T-cell proliferation
  • Enhancement of wound healing
  • Facilitation of apoptosis and clearance of spent neutrophils
  • Modulation of cytokine production
  • Neurotransmitter synthesis
  • Reduction of histamine levels
  • Reduction of infection susceptibility
  • Reduction of necrosis/NETosis

In conclusion, essential nutrients are unquestionably required for numerous crucial metabolic and biochemical processes in the body. It is certainly time to focus on the nutrition status of those at risk for and infected with the virulent COVID-19 pathogen, as well as those at risk for other potential infectious and metabolic disorders. Randomized trials and population studies are needed to explore, and hopefully confirm, essential nutrition intervention.


Carr AC. A new clinical trial to test high-dose vitamin C in patients with COVID-19. Crit Care. 2020 Apr 7;24(1):133.

Carr AC, Maggini S. Vitamin C and Immune Function. Nutrients. 2017 Nov 3;9(11).

Ely JT. Aneurysm: prevention and nonsurgical repair. Med Sci Monit. 2004 Jan;10(1).

Lykkesfeldt J, Michels AJ, Frei B. Vitamin C. Adv Nutr. 2014 Jan 1;5(1):16-8.

Mertens MT, Gertner E. Rheumatic manifestations of scurvy: a report of three recent cases in a major urban center and a review. Semin Arthritis Rheum. 2011 Oct;41(2):286-90.

Olmedo JM, Yiannias JA, Windgassen EB, Gornet MK. Scurvy: a disease almost forgotten. Int J Dermatol. 2006 Aug;45(8):909-13.

Padayatty SJ, Doppman JL, Chang R, et al. Human adrenal glands secrete vitamin C in response to adrenocorticotrophic hormone. Am J Clin Nutr. 2007 Jul;86(1):145-9.

Pullar JM, Carr AC, Bozonet SM, et al. High Vitamin C Status Is Associated with Elevated Mood in Male Tertiary Students. Antioxidants (Basel). 2018 Jul 16;7(7).

Wang AH, Still C. Old world meets modern: a case report of scurvy. Nutr Clin Pract. 2007 Aug;22(4):445-8.

Weinstein M, Babyn P, Zlotkin S. An orange a day keeps the doctor away: scurvy in the year 2000. Pediatrics. 2001 Sep;108(3)

Tag(s): Treatment

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