Research suggests early and high intravenous does could help to fight the deadly disease

The COVID-19 pandemic, first reported in Wuhan, China, has now spread to many countries, causing a severe public health burden.

Currently, there is no vaccine or specific antiviral drug for this deadly disease, but research based on the outcome of previous clinical studies indicates that early and high intravenous doses of vitamin C could provide treatment.

A study led by Virginia Commonwealth University (VCU), found that patients who received intravenous vitamin C spent significantly fewer days in intensive care and in the hospital overall.1 On average, the vitamin C group spent three fewer days in the ICU (seven days compared to 10) at day 28 and a week less in the hospital overall (15 days versus 22) by day 60 than the placebo group.

Separate research has also found that vitamin C may help to reduce the length of time spent in intensive care. In a meta-analysis of controlled trials, it was found in 12 trials with 1,766 patients, that vitamin C reduced the length of ICU stay on average by 7.8 per cent. In six trials, orally administered vitamin C was found to reduce the length of ICU stay by 8.6 per cent, and in three trials in which patients needed mechanical ventilation for over 24 hours, vitamin C shortened the duration of mechanical ventilation by 18.2 per cent.2 Based on these findings and the low cost of administering vitamin C, the authors said that further studies were recommended.

Vitamin C and COVID-19

A group of hospitals in New York is treating its most critical COVID-19 patients with high doses of vitamin C. Dr Andrew G Weber, a pulmonologist and critical care specialist with Northwell Health, which has 23 hospitals in New York State said: “The patients who received vitamin C did significantly better than those who did not get vitamin C.”

His patients are being given doses of 1500 milligrams three to four times a day.

Dr Enqian Mao, chief of emergency medicine at Ruijin Hospital in Shanghai, also treated 359 COVID-19 patients in critical care units with high-dose vitamin C, ranging from 10,000 to 20,000 mg a day for seven to 10 days. None of the patients died. 

In a report of 29 patients with COVID-19 pneumonia, 27 (93%) showed increased hsCRP, a marker of inflammation and oxidative stress.3 Activation of Nrf2 (a protein that regulates the expression of antioxidant proteins that protect against oxidative damage triggered by injury and inflammation) signalling plays an essential role in preventing cells and tissues from injury induced by oxidative stress. Vitamin C is an important component of the cellular antioxidant system and therefore could be beneficial to critical care management.4

How much vitamin C should you take?

The NHS recommends we get 40 mg a day and does not advise that anyone take very high doses of vitamin C without medical supervision (it states that taking more than 1,000 mg a day can cause stomach pain and diarrhoea).

Because of illness or lifestyle factors, some people are advised to take in higher amounts of vitamin C. Last year, a researcher from Oregon State University (OSU), USA, advised that people with metabolic syndrome should increase their intake because they tend to have lower circulating levels. This is because conditions such as obesity affect how the body processes vitamins and minerals.

Professor Maret Traber, from the OSU College of Public Health and Human Sciences and at Oregon State’s Linus Pauling Institute, USA, said in an OSU statement: “People with metabolic syndrome can eat the same amount of vitamin C as people without metabolic syndrome but have lower plasma concentrations of vitamin C.” Lower plasma levels are caused by a chain of events. Along with vitamin E, vitamin C is an antioxidant that defends cells from oxidative stress. It was suggested, in findings published in Redox Biology,5 that the type of diet that leads to metabolic syndrome can prompt imbalances in the gut microbiome [dysbiosis]. This leads to impaired gut function which, in turn, contributes to toxins in the bloodstream; the result of which is vitamin C depletion and impaired trafficking of vitamin E.

Traber explained that gut dysbiosis and accompanying injury to the gut causes bacterial cell walls to leak from the gut and slip into circulation in the body. This then tricks the immune system into launching a response in which white blood cells (neutrophils) attack with hypochlorous acid (bleach) depleting vitamin C. “The white blood cells are scrubbing with bleach and that destroys vitamin C,” said Traber. “The body is destroying its own protection because it got tricked by the gut dysbiosis into thinking there was a bacterial invasion.”

The research suggested that large percentages of populations where metabolic syndrome is common may, as a result, be deficient in vitamin C, with implications for a compromised immune system. Lifestyle interventions such as eating a rainbow coloured diet with plenty of vegetables and some fruit, exercising, cutting out smoking and reducing less healthy food choices would be an approach for anyone wishing to tackle metabolic syndrome.

Dietary sources of vitamin C

If you were looking to supplement with vitamin C, chances are the shops are out. The good news is, you should be able to get all the vitamin C you need from your daily diet. Vegetables and fruits are all sources of vitamin C, with some packing a greater punch than others. Red bell peppers, kiwi fruits and navel oranges are among the top sources, as well as broccoli, Brussels sprouts, tomatoes, avocado, blueberries, asparagus and apple.

Some fortified foods such as breakfast cereals will also be fortified with vitamin C — usually listed as ascorbic acid.


  1. https://jamanetwork.com/journals/jama/article-abstract/2752063
  2. https://www.mdpi.com/2072-6643/11/4/708
  3. https://www.ncbi.nlm.nih.gov/pubmed/32026671
  4. https://www.sciencedirect.com/science/article/pii/S2590098620300154#bb0035
  5. https://www.ncbi.nlm.nih.gov/pubmed/30640128