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The Truth about Vitamin D and COVID-19

The most important fact that is often overlooked is that these supplements have been studied and do not work.

This article was first published in The Montreal Gazette.

I am often asked if there is a simple way to prevent or cure COVID-19. I can assure you there is not. If there were, I would not have sat casually by as millions of people around the world got sick and died. Not being a Bond villain, I derive no pleasure from wide-scale human suffering, nor do I enjoy not being able to see my friends. I don’t endorse any vitamin or mineral as a COVID cure because they simply do not work.

You will, if you wade through the morass of misinformation on the internet, find many posts and videos advocating for zinc, Vitamin C or Vitamin D as COVID cures. They promise to simultaneously prevent infections, cure the disease, save lives and thereby make lockdowns and vaccines unnecessary.

These claims are, to put it bluntly, wrong. Central to these vitamin and supplement theories is the notion that doctors are either unaware of their benefits or so far corrupted by the pharmaceutical industry that they are deliberately ignoring their obvious benefits.

There are multiple reasons why this type of conspiracy theory would be untrue. Again, most doctors are not so morally reprehensible that they would watch millions die and do nothing. Second, Pfizer (and most large drug companies) also sell vitamins and supplements. A dose of vaccine and a bottle of vitamins both cost about $20 to $30, so Pfizer would not have spent $2 billion developing a vaccine when they could have sold us vitamins at the same price and made a larger profit. Unfortunately, conspiracy theories usually require the actors involved to behave irrationally and counter to their own self-interest.

But the most important fact that is often overlooked is that these supplements have been studied and do not work. The COVID A to Z Randomized Trial tested ascorbic acid (Vitamin C), zinc and a combination of the two as a treatment for COVID-19. Between April and October 2020, researchers recruited patients diagnosed with COVID-19 and randomly assigned them to receive nothing, zinc, Vitamin C or both. Neither zinc, nor Vitamin C, nor the combination, improved symptoms, the risk of hospitalization or the risk of death. As the accompanying editorial pointed out, these two supplements failed to live up to their hype.

Vitamin D is another popular supposed COVID cure, though many of its claims to reduce heart disease or cancer have not panned out. I was willing to entertain the possibility that it might work for COVID-19. But the only published trial about Vitamin D and COVID-19 shows that it does not. Researchers in Brazil randomized hospitalized COVID patients to get either a placebo or 200,000 units of Vitamin D. This is a massive dose and 20 times higher than what most people take per week. For those patients, their blood levels of Vitamin D went up. They just didn’t get better any faster. Admission to the ICU, being put on a ventilator and mortality were the same in both groups.

Many people, including British MP David Davis, got excited when a preprint article was posted online and suggested that Vitamin D could reduce COVID mortality by a whopping and somewhat implausible 60 per cent and called for widespread Vitamin D use. The study, though, had a few problems and upon closer inspection was not a standard randomized trial. It was rejected by the Lancet, and its preprint server now says, “We have removed this preprint due to concerns about the description of the research in this paper. This has led us to initiate an investigation into this study.”

There is a very good reason why vitamins and minerals are not used to treat COVID-19. It has nothing to do with conspiracies or bias or corruption. Doctors would happily use vitamins to cure patients with COVID-19. The problem is we’ve tried that. They don’t work.


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