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Source: United Kingdom – Executive Government & Departments

Three reviews, from Public Health England (PHE), National Institute for Health and Care Excellence (NICE), and the Royal Society respectively, have looked at Vitamin D and COVID-19.

Prof Keith Neal, Emeritus Professor of the Epidemiology of Infectious Diseases, University of Nottingham, said:

“There is no good evidence supporting vitamin D improving your COVID-19 risks.

“There is plenty of good evidence to take low dose supplements between September 21st and March 21st through the winter to avoid vitamin D deficiency and to improve general health.

“For those people who are not going out or at risk of deficiency this can be extended into other times of the year.

“The NICE guidance needs to be better advertised to everyone.”

Prof Adrian Martineau, Clinical Professor of Respiratory Infection and Immunity, Queen Mary University of London, said:

“Today sees the publication of three new reports reviewing the scientific evidence linking vitamin D deficiency to increased risk of acute respiratory infections and COVID-19.

“1. The report from the Scientific Advisory Committee on Nutrition (SACN) reviews results of clinical trials that have investigated whether vitamin D supplements can reduce risk of acute respiratory infections other than COVID.  In particular, they identify 5 relevant trials that have been done since our review of the field published in the BMJ in 2017.  In that review, pooling of data from 25 trials showed a modest protective effect of vitamin D against respiratory infections, that was stronger in those who had low vitamin D levels at baseline.  SACN rightly highlight that the results of the 5 new trials they have identified are mixed, and they conclude that overall there is insufficient evidence to recommend vitamin D to reduce risk of acute respiratory infections.  They also correctly highlight that no trials of vitamin D for prevention of COVID have yet been done – thus, results of trials looking at prevention of other respiratory infections can’t readily be generalised to COVID-19.

“Two limitations of the SACN report are that a) no attempt is made to analyse pooled data from the trials, and b) that a number of seemingly relevant trials were not considered.  My group is in the final stages of an updated meta-analysis, including data from the new trials identified by SACN as well as nine others.  We hope to submit our findings next month.

“2. The report from the National Institute for Health and Care Excellence (NICE) reviews five papers published in peer-reviewed journals that have investigated potential associations between low vitamin D levels with a) susceptibility to COVID-19, and b) adverse outcomes of COVID-19.  The authors of this report are right to highlight that these studies are limited by their observational nature – where lower vitamin D status is linked to poorer outcomes, it is impossible to know whether associations are causal.  The report concludes that there is no evidence to support taking vitamin D to prevent or treat COVID-19; it highlights existing UK Government advice on daily vitamin D supplementation to maintain bone and muscle health.

“Vitamin D enthusiasts will point to a large number of other studies published on pre-print websites that were not included in this review.  However, these studies have not yet undergone peer review, so their findings should not be relied on to guide clinical practice or public health policy.  The report makes no comment on the need for research into vitamin D and COVID-19.

“3. By contrast, the shorter report from the Royal Society adopts a more upbeat tone in considering the potential for vitamin D to have a role in prevention or treatment of COVID-19, and there is a stronger focus on the findings of laboratory studies that underpin scientific interest in this field.  In addition to calling for the government to provide a stronger public message around existing recommendations for vitamin D intake, there are specific recommendations for research into whether vitamin D deficiency might contribute to increased COVID-19 risk seen in elderly and BAME populations.

“This call for further research into vitamin D deficiency and COVID-19 is welcome – and if UK residents are interested in contributing to such an endeavour, I would urge them to join 8,000 others by signing up to the COVIDENCE UK study ( – a national longitudinal study involving on-line questionnaires that is examining risk factors for COVID-19 with a particular focus on vitamin D.”

SACN rapid review:

NICE rapid evidence summary:

Royal Society preprint review:

All our previous output on this subject can be seen at this weblink:

Declared interests

Prof Keith Neal: “No conflicts.”

Prof Adrian Martineau: “I led the 2017 the BMJ meta-analysis of data from clinical trials of vitamin D supplementation to reduce risk of acute respiratory infections.  I am lead investigator for the COVIDENCE UK study, investigating the role of vitamin D deficiency and other risk factors for COVID-19.  I do not have any financial conflicts of interest to declare.”

MIL OSI United Kingdom