There are many fans of so-called alternative medicine (SCAM) who think that vitamin C is the answer to COVID (and many other ailments). Here, for instance, is a press release from Damien Downing (we already encountered him in my last post):

Vitamin C and COVID-19 Coronavirus

by Damien Downing, MBBS, MRSB and Gert Schuitemaker, PhD


Orthomolecular Medicine News Service, Feb 28, 2020

There is only one existing treatment for the new coronavirus: vitamin C.

Vitamin C supports your immune system. Vitamin C helps to kill the virus and reduces the symptoms of infection. It’s not a COVID “cure,” but nothing is. It might just save your life, though, and will definitely reduce the severity of the infection.

If someone tells you it’s not proven, consider two things:

    1. Nothing is proven to work against COVID-19, because it is a new virus.
    2. Vitamin C has worked against every single virus including influenzas, pneumonia, and even poliomyelitis.

What to do

If you do nothing else, start taking vitamin C right away; at least 3 grams a day, spread right across the day. That’s a 1,000 milligram capsule every 8 hours, or a level teaspoon of powder dissolved in a pint or so of water, drank all through the day.

If you’re smart and motivated, do all the other things recommended in our previous release Vitamin C Protects Against Coronavirus (

When and if you catch a bug that might be COVID-19, simply increase your vitamin C intake: a rounded teaspoon (that’s 4 to 5 grams) in water (which helps to keep you hydrated) every 3 or 4 hours. And keep on taking it.

Do you consult a doctor? Do you self-isolate? Yes and yes. Of course you do; that’s your duty to others.

Vitamin C and the other measures are what you do for yourself…

Damien Downing’s press release did not age all that well, I fear. The evidence to support his claims is not just flimsy, it is negative. Let me show you the most recent (October 2021) systematic review of the subject:

Background and aims: Vitamin C has been used as an anti-oxidant in various diseases including viral illnesses like coronavirus disease (COVID-19).

Methods: Meta-analysis of randomized controlled trials (RCT) investigating the role of vitamin C supplementation in COVID-19 was carried out.

Results: Total 6 RCTs including n = 572 patients were included. Vitamin C treatment didn’t reduce mortality (RR 0.73, 95% CI 0.42 to 1.27; I2 = 0%; P = 0.27), ICU length of stay [SMD 0.29, 95% CI -0.05 to 0.63; I2 = 0%; P = 0.09), hospital length of stay (SMD -0.23, 95% CI -1.04 to 0.58; I2 = 92%; P = 0.57) and need for invasive mechanical ventilation (Risk Ratio 0.93, 95% CI 0.61 to 1.44; I2 = 0%; P = 0.76). Further sub-group analysis based on severity of illness (severe vs. non-severe), route of administration (IV vs. oral) and dose (high vs. low) failed to show any observable benefits.

Conclusion: No significant benefit noted with vitamin C administration in COVID-19. Well-designed RCTs with standardized control group needed on this aspect.

What does that tell us?

I think it suggests three things:

  • Damien Downing might be suffering from proctophasia,
  • we would be ill-advised to follow the advice of such pseudo-experts,
  • vitamin C is not the solution to COVID-19 infections.

6 Responses to And again: is vitamin C the solution for COVID-19 infections?

  • I find the metaanalysis tricky, as it mixes different therapies, which can’t be compared. The only study, which reaches Vitamin C doses recommended by Linus Pauling is the study of Zhang (2021).

    Linus Pauling:
    Zhang (2021):

    The only study without major fails regardng design was the study Zhang 2021. Thus, I would focus on this study alone and forget about the rest.

    Even though the study of Zangh (2021) failed to trigger significance for reduction of overall mortality, they had as secondary finding statistically significant improvements for patients with SOFA (Sequential Organ Failure Assessment).

    Thus I would not doom Vitamin C to be without value in treatment of Covid 19 patients but keep in mind its favourable effects on persons showing SOFA (Sequential Organ Failure Assessment) where it could safe lifes.

    • Interesting points.
      However, on the basis of secondary results of a pilot study, I would not speak of ‘favourable effects’.

      • I think the metastudy and especially the study of Zangh et all. (2021) is a good proof that vitamin C does not cure Covid 19. However, it can be an important part of therapy of problems caused by heavy diseases. Covid 19 is a virus and it has to be removed by our immune system – and nothing but our immune system. However, we can strengthen our immune system in many ways – vaccination being an important part of it.

        If we look where we find vitamin C in the world around us – our processed food often contains ascorbic acid. The job it has to do there is to protect from degradation.

        Same seems to work for living tissue which is saturated with ascobic acid.

        A body fighting a strong fight against a deadly disease may turn of organs to focus on the one fight and putting all affords in the one thing that may be a last chance to overcome the problem. It’s like turning off all computer programs and maybe even its security systems to run the one program that needs lots of capacity and which is urgently needed. I see SOFA (Sequential Organ Failure Assessment) not as a process of dying but as a last try of the body to overcome the problem with all that is left inside. A fight that will be lost most of the time, but it is a very last chance to do so.

        The organs turned off are in danger to degrade – and Vitamin C could keep them safe from it until the war against the disease is won and the body can recover and turn on every system, again.
        Maybe Vitamin C therapy would work in cases of sepsis, too.

        I write these lines not as a doctor in medicine but as biologist. I think that it is useful to take part at medical discussions also as biologist, as we see things from a different viewpoint.

        The experts of medicine see the problem, the illness and things that do not work good in a very deep way. The biologist sees the things the way they work in normal order and the mechanisms that work to keep things balanced or bring them back to balance if a problem has occured.

        The understanding of mechanisms and strategies to safe and heal a living system is an important part of keeping them healthy or to heal them. A therapy which not just tries to interrupt the principles and mechanisms of illness but which uses understanding of natural mechanisms which try to do so, should bring much better therapies. It’s like our second leg which gives so much more strength than just a single one.

        • yes, it’s good to involve biologists and others in discussions about medicine.
          yet, if you believe that the mode of action is not something that medics are focussing on, you are mistaken.
          as to vitamin C, we know a lot of its mechanisms but we do not know much about its clinical effectiveness. jumping to conclusions is a dangerous sport.

        • As a biologist then, you should know that speculation is all well and good, but worth very little until you actually test it. There is a reason science is liberal in its hypotheses and conservative in its conclusions. Vitamin C boosters have long been reckless in both, up to and including Nobel winner level.

          And sure, cross-discipline discussions can be a productive source of alternate insights; but you say it as if this doesn’t already happen. (Although perhaps it doesn’t happen enough? You are welcome to make that argument if so.)

          Also worth leaving this here:

          Although often as not AltMed doesn’t even bother with in-vitro before heading directly to market. Which probably tells us twice as much about the true nature of our universe than all the Vitamin C research ever published.

  • I have reported Downing to the ASA. If anyone else wants to, this is the link:

    He is registered with the GMC, and is obviously in breach of his licence terms by failing to follow evidence based clinical practice.

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