Vitamin D – time for action

Article written by Christine Clark

Is there case for mass vitamin D supplementation to mitigate the effects of covid-19?

There are now more than 40 studies demonstrating that having optimal blood levels of 25(OH)-vitamin D (75-150 nmol/L) reduces covid-19 risks; these include reduced risk of infection, reduced risk of severe disease and reduced risk of dying.  These findings are further bolstered by studies relating vitamin D status and covid death rates to proximity to the equator and exposure to sunlight. Indeed we have highlighted the mounting evidence for vitamin D on these pages previously.

Many researchers now regard the evidence as being overwhelming. The UK government has implicitly endorsed this view by mandating the supply of the vitamin to the ‘clinically extremely vulnerable’ (starting in January 2021). At the same time further reviews and a trial (‘Coronavit’) have been commissioned to determine whether being vitamin replete can reduce the risk of dying from covid-19 infection.

Researchers have suggested that this cautious approach reflects a lack of risk/reward understanding amongst health authorities given that the evidence for the protective role of vitamin D is extensive, most of the UK population is vitamin deficient for at least half the year (even without lockdown) and supplements are cheap, available and non-toxic.  The mainstay of the case against recommending or providing vitamin D supplements is that there is insufficient evidence to justify such a step but this is an argument that is increasingly difficult to sustain.

Although vaccination for covid -19 has now started it will be some months before the majority of the population has been vaccinated and so measures to mitigate the impact of infection will continue to be important. As Haug and colleagues argue, “the case for vitamin D is as follows: little downside, low cost, lives at stake, and a high probability of a beneficial effect. *Not* to act is also a choice.”1 It is hard to escape the conclusion that health authorities should be recommending vitamin D supplementation for everyone, immediately. 


Haug EG et al. Vitamin D and COVID-19: Is There a Lack of Risk/Reward Understanding Among Health Authorities? Preprint November 2020 DOI: 10.13140/RG.2.2.13972.12164

Be sure to subscribe for news directly to your inbox.