Vitamin D: The Truth About An Alleged Covid ‘Cover-up’
Now open: Certificate Course in Management of Covid-19 by Govt. Of Gujarat and PlexusMDKnow more...Now open: Certificate Course in Management of Covid-19 by Govt. Of Gujarat and PlexusMDKnow more...
Get authentic, real-time news that helps you fight COVID-19 better.
Install PlexusMD App for doctors. It's free.
Why vitamin D?

It plays a role in immunity and it's already recommended that everyone in the UK take the supplement in the winter, with those at higher risk of vitamin D deficiency advised to take it all year round. So far, no research has shown a convincing enough effect to support higher doses to prevent or treat illness - although this doesn't mean that won't change in the future.

What do studies say?

Many studies have shown an association between vitamin D and Covid outcomes, but the evidence is largely observational - meaning it looks at what happens to people with higher and lower levels of vitamin D without controlling for other factors. Observational studies do show certain groups are both more likely to have vitamin D deficiencies and to catch Covid - older people, people with obesity, people with darker skin.

It may be that a deficiency is the reason these groups are at higher risk, or there may be other health and environmental factors driving both a fall in levels of vitamin D and greater susceptibility to the virus. The NHS recommends people with dark skin, should consider taking a vitamin D supplement throughout the year. Levels of the vitamin can also fall as a consequence, rather than a cause, of illness.

Spanish studies

One particular paper from the University of Barcelona has attracted attention, claiming to be just this type of study. It suggested vitamin D had staggering success, with an 80% reduction in intensive care admissions and a 60% reduction in Covid deaths. It was widely shared online. But it has since been withdrawn over concerns about the description of the research.

Vitamin D was given to whole wards which often care for patients based on how ill they are, not randomly assigned to individuals. And the Covid patients in the study who died had radically different levels of the vitamin to start with, suggesting they were more ill in the first place. Although vitamin D deficiency was a well-established risk factor among people who die in intensive care, vitamin D supplementation alone has always failed to reduce the risk of those patients.

What's the harm?

When the findings fit in with people's world views - for example that "natural things can't harm you", Prof Sander Van der Linden, a social psychologist at the University of Cambridge explained - this makes them more likely to be shared. While the online worlds of natural health and alternative medicine, and of people who are ideologically anti-vaccination are distinct, they can overlap.

Anti-vax accounts are "densely connected to other topics - religion, herbal and alternative medicine, the natural community," says Prof Van der Linden. Vitamin D is relatively safe so it may not appear to be the most harmful of misinformation. The danger, Prof Van der Linden explains, is when people suggest the supplement is a miracle cure and should be substituted for vaccines, masks and social distancing.

1 share