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Is Vitamin C useful for the prevention and treatment of COVID-19?

There are no absolutely proven therapies for COVID-19 as yet. It is possible that strategies that improve overall resistance to viral respiratory infections will help. In addition Vitamin C has been used to treat patients in Intensive Care Units (ICU) with COVID-19 and other forms of pneumonia. This article gives a brief overview of the use of Vitamin C in these situations.

Linus Pauling advocated using the Vitamin C to protect health and for the treatment of the common cold and cancer. He wrote:

It is wise to carry some 500-mg tablets of ascorbic acid with you at all times. At the first sign that a cold is developing begin the treatment by swallowing one or two 500-mg tablets. Continue the treatment for several hours by taking an additional tablet or two tablets per hour1.

He hypothesized that Vitamin C increases the cellular production of Interferon. At the moment synthetic Interferon is being used to treat many patients with COVID-19 in Hong Kong.

As an aside, Linus Pauling is one of only four people to win two Nobel Prizes, one of the others, Fred Sanger of Cambridge University, was awarded one of his for advances in PCR DNA sequencing, the technologies behind the COVID-19 PCR test.

A recent meta-analysis, that is a statistically powerful study pooling data from several trials, found that Vitamin C administration decreased the duration of Upper Respiratory Tract Infection (such as viral cold)  by 1.6 days in children. The investigators said “considering the frequency of Upper Respiratoy Tract Infection, the inappropriate prescription of antibiotics, and the safe nature of vitamin C, its supplementation is justified2".

A meta-analysis by Cochrane found mixed evidence but stated:

One large trial with adults reported benefit from an 8 g therapeutic dose at the onset of symptoms, and two therapeutic trials using five-day supplementation reported benefit ... given the consistent effect of vitamin C on the duration and severity of colds in the regular supplementation studies, and the low cost and safety, it may be worthwhile for common cold patients to test on an individual basis whether therapeutic vitamin C is beneficial for them.

Certainly Vitamin C can form part of your viral prevention strategy, even catching the common cold can be stressful now when the COVID-19 early symptoms are similar. However, COVID-19 is not the common old, it is a far more serious respiratory viral infection that can cause pneumonia.

There have recently been reports of intravenous Viatmin C being used to treat hospital patients with COVID-19 in the US3. According to a New York Post article, seriously sick coronavirus patients in New York state’s largest hospital system are being given large doses of vitamin C intravenously. Dr Andrew G Weber, a pulmonologist and critical-care (ICU) specialist, said his intensive-care patients with the coronavirus immediately receive 1,500 milligrams of intravenous vitamin C. "The patients who received vitamin C did significantly better than those who did not get vitamin C,” he said, “It helps a tremendous amount, but it is not highlighted because it’s not a sexy drug"4.

There is currently a trial taking place in China to formally investigate whether Vitamin C is effective for COVID-19. According to the investigators, “When sepsis happens, the cytokine surge caused by sepsis is activated, and neutrophils accumulate in the lungs, destroying alveolar capillaries. Early clinical studies have shown that vitamin C can effectively prevent this process. In addition, vitamin C can help to eliminate lung fluid by preventing the activation and accumulation of neutrophils and reducing lung damage”5.

There is general interest in using Vitamin C in an ICU setting. A meta-analysis of trials found that using Vitamin C reduced the length of ICU stay. The authors concluded, “Given the insignificant cost of vitamin C, even an 8% reduction in ICU stay is worth exploring. The effects of vitamin C on ICU patients should be investigated in more detail”6.

Vitamin C is a cheap and safe nutritional supplement which may prevent the common cold but there is no evidence that it can prevent more serious respiratory infections. Vitamin C intravenously is being investigated and showing promise for the prevention and treatment of the complications of COVID-19 in an ICU setting. The on-going trials will hopefully identify if this is the case.


1. Pauling, Linus (1970). "Vitamin C and the Common Cold"JAMA (1 ed.). San Francisco: W. H. Freeman. 216 (2): 332. doi:10.1001/jama.1971.03180280086025OL 4914696MPMC 2156371PMID 5107925.

2. Efficacy of vitamin C for the prevention and treatment of upper respiratory tract infection. A meta-anlaysis European Journal of Clinical Pharmacology volume 75, pages303–311(2019). Published: 21 November 2018

3. Vitamin C deployed in big doses to help treat coronavirus patients. (2020, March 28). Retrieved from

4. Mongelli, L., & Golding, B. (2020, March 25). New York hospitals treating coronavirus patients with vitamin C. Retrieved from

5. Vitamin C Infusion for the Treatment of Severe 2019-nCoV Infected Pneumonia - Full Text View. (n.d.). Retrieved from

6. Hemilä, Harri, Chalker, & Elizabeth. (2019, March 27). Vitamin C Can Shorten the Length of Stay in the ICU: A Meta-Analysis. Retrieved from

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Topics: COVID-19, Health & Wellness

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