No Sign Vitamin D Protects Against COVID-19

There’s no sign vitamin D protects against COVID-19, says Emily Henderson writing in Medical Life Sciences on June 6, 2021. She relies on a study from McGill University published in PLOS Medicine five days earlier. Their researchers feel so strongly about this that they recommend prioritizing other therapeutic / preventative avenues.

This Finding Also Runs Counter to Generally Accepted Opinion

Previous studies did suggest vitamin D cuts the risk of contracting COVID-19, Emily Henderson concedes. But the McGill researchers say they found ‘no evidence supporting Vitamin D levels reduce the likelihood COVID-19 susceptibility, hospitalization, or severity’. However, they admit their finding does have these two limitations:

1… First, their results do not apply to individuals with vitamin D deficiency

2… Therefore it remains possible they may benefit from supplemental vitamin D

Not Easy Proving No Sign of Vitamin D Protecting Against COVID-19

It’s never an easy task to prove something does not exist. Several researchers attempted to prove or disprove the relationship early in the pandemic. As one of the McGill University researchers, Guillaume Butler-Laporte, study co-author and physician puts it:

‘Most vitamin D studies are very difficult to interpret, since they cannot adjust for the known risk factors for severe COVID-19. Such as for example older age or having chronic diseases, which are also predictors of low vitamin D.’ He goes on to suggest the best way to prove the case either way would be randomized trials.

However, these are ‘complex and resource intensive, and take a long time during a pandemic,’ he says. Therefore the team used the Mendelian randomization method instead.

The McGill University researchers mined data from the largest consortium of COVID-19 cases and controls. And the largest study on genetic determinants of vitamin D levels. They concluded there’s no genetic sign vitamin D protects against COVID-19. Do you believe this is case closed, or is there more to it than this?