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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 Martin Hewison, Professor of Molecular Medicine, University of Birmingham, said:
“The NICE and SACN rapid reviews on the possible benefits of vitamin D in Covid-19 are a welcome addition to the recent discussions on this topic. Both reports conclude that, at present, there is no clear evidence that vitamin D supplementation protects against Covid-19 infection or reduces the inflammatory disease that follows infection. However, it is important that the studies of vitamin D and acute respiratory tract infections reviewed by NICE and SACN varied considerably. Some of the populations studied had pre-existing respiratory conditions, and in studies where vitamin D supplementation was employed, the type and dose of supplementation varied. It is also important to recognise that although there are well described mechanisms for antimicrobial and anti-inflammatory actions of vitamin D, we still do not know what levels of vitamin D are required to achieve these effects in humans, particularly for Covid-19 infection. Both NICE and SACN emphasised that it is important to maintain healthy levels of vitamin D for general health, particularly musculoskeletal function. This may require supplementation with vitamin D (the level currently recommended by the government is 10 micrograms/day (400 IU/day)) during the winter months, or all year round for people who have darker coloured skin pigmentation, or people who are housebound or who cover-up when outside. NICE and SACN indicated that they will continue to review the effects of vitamin D on Covid-19 as new data become available.”
Dr Benjamin Jacobs, Consultant Paediatrician, Royal National Orthopaedic Hospital, said:
“The Royal Society has issued a brave and urgently needed message to the UK Government, challenging them to provide a “stronger approach to Vitamin D”.
“This is much needed. Other bodies such as NICE continue to stick with weak advice that people should “consider” taking a supplement for skeletal health. Although there is no evidence linking Vitamin D to better COVID-19 outcomes yet, there are good reasons to suspect a link with COVID-19. By the time the clinical trial results emerge many people will have missed out on the benefit of Vitamin D for non-COVID reasons, for which there is already clear evidence. As a front-line paediatrician who continues to see children suffering the effects of Vitamin D Deficiency including rickets, convulsions and cardiomyopathy, I feel we need not wait for more Vitamin D COVID treatment trial results. Even if COVID-19 turns out not to be a reason to take Vitamin D there are plenty of health reasons for those at risk of deficiency to take it year-round and for all of us to take it in the winter months.
“Vitamin D is remarkably safe and cheap and now is the time to act on this Royal Society advice.”
Prof David Richardson, Scientific Adviser to the Council for Responsible Nutrition UK, a trade association representing the food supplement industry, said:
“Food supplements are regulated as foods and are intended to correct nutritional deficiencies, maintain an adequate intake of essential nutrients and to support specific physiological functions, such as the immune systems. They are not intended to treat, prevent or cure diseases.
“Diet and nutrition surveys in the UK (NDNS) have shown a downward trend in intakes of vitamins and minerals over nine years and significant sections of the population do not achieve the recommended amount per day or even reach what we call the Lower Reference Nutrient Intake (LNRI). Some groups of the population are known to be at risk of deficiency of the very nutrients need to support the immune functions. If the immune system is weakened, people become more susceptible to disease.
“The NICE report refers to therapeutic uses of nutrients for prevention or cure. There is no evidence at the moment that any nutrient would prevent or cure COVID-19. However, the evidence in general for associations between good nutrition and avoidance of nutritional deficiencies and support of the immune function are very strong indeed. The NICE report also reports on studies using massive doses of vitamin D for therapeutic use under medical supervision and this sort of study bears absolutely no relevance to the amounts in a food supplement for use by the general population.
“The Royal Society review is absolutely correct in highlighting the need for the UK Government to strengthen its advice on avoiding vitamin D deficiency during the COVID-19 pandemic. The other nutrients that contribute to the functioning of the normal immune system include vitamin A, including beta-carotene, the B vitamins (folate, vitamins B6 and B12), vitamin C and the essential minerals and trace elements iron, copper, zinc and selenium.
“The SACN and NICE reports together provide comprehensive information on vitamin D and COVID-19, but fail to bring home the headline and critical messages for general health on avoidance of deficiencies and identification of suboptimal intakes of vitamin D in targeted groups of patients and in the distinct and highly sensitive populations, e.g. elderly people, particularly the over-70s, care home residents, ethnic minorities and those with low exposure to sunlight.
“Food supplements containing vitamin D and other essential nutrients are safe and effective ways to support the immune system. The vulnerable groups tend to have suboptimal nutritional status and low intakes of the nutrients needed to support the immune system and if the immune system is weakened for whatever reason the people may be more susceptible to infection.
“Research is needed now to assess nutritional status of micronutrients as possible and modifiable risk factors for COVID-19, and other confounding variables such as obesity, diabetes and hypertension.”
Dr Will Carroll, Honorary Reader in Child Health, Keele University said:
“These statements from NICE, SACN and Royal Society are welcome. They highlight the lack of evidence in this area, specifically with respect to COVID-19 infection.
“The best way to identify whether vitamin D has a role to play in helping the UK respond to the COVID-19 pandemic is to conduct a randomised clinical trial.
“As any effect is likely to reduce risk by a small amount, rather than prevent infection, it will have to be a fairly large study with at least 5000-6000 participants.”
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 (www.qmul.ac.uk/covidence) – 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: https://app.box.com/s/g0ldpth1upfd7fw763ew3aqa3c0pyvky
NICE rapid evidence summary: https://www.nice.org.uk/advice/es28/chapter/Key-messages
Royal Society preprint review: https://royalsociety.org/-/media/policy/projects/set-c/set-c-vitamin-d-and-covid-19.pdf
All our previous output on this subject can be seen at this weblink:
www.sciencemediacentre.org/tag/covid-19
Declared interests
Prof Martin Hewison: “No interests to declare.”
Dr Benjamin Jacobs: “No conflicts of interest.”
Prof David Richardson: “I am Scientific Adviser to the Council for Responsible Nutrition which is a trade association representing the food supplement industry. CRNUK is leading the industry in the focus on the quality of its technical and scientific work. Members are the leading manufacturers and suppliers of food supplements in the UK. I am a nutritional biochemist BSc, MSc, PhD, FRSM, FIFST and Visiting Professor of nutritional sciences at the University of Reading. I was previously on the UK COMA (before SACN) and the industry representative on the UK Expert Group on risk assessment of vitamins and minerals for use in food supplements (EVM). I run my own specialist consultancy on nutrition and food science.”
Dr Will Carroll: “Dr Carroll is in the process of preparing a research proposal to specifically address this research question.”
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.”