Study: Vitamin D won’t limit risk, severity of Covid-19

‘New Cornell-led research finds “little to no evidence” of a link between a person’s normal blood levels of vitamin D and risk of getting COVID-19, or the severity of an infection, in the most comprehensive study of its kind to date.

‘Multiple studies had suggested an association between vitamin D and COVID-19 risk, raising hopes that vitamin D supplements might help to prevent or minimize infections – speculation that has received widespread media attention and boosted consumer interest.

‘The new study, however, which analyzed a publicly available genomic data bank and 38 different COVID-19 studies worldwide – a total sample including nearly 1.4 million people – does not support those claims.’

Read here (Cornell Chronicle, May 7, 2021)

Matt Hancock orders third review on link between vitamin D and Covid

‘A third review into the link between vitamin D and Covid has been ordered by the UK health secretary as more studies suggest that having low levels of the “sunshine hormone” raises the risk of death.

‘Matt Hancock has again asked the National Institute for Health and Care Excellence (Nice), which sets NHS England clinical guidelines, and Public Health England (PHE) to “re-review” their prior appraisals, after the authorities began “encouraging” people to take vitamin D supplements rather than merely “advising” it.

‘Nice has twice said there was not sufficient causal evidence to support the use of vitamin D in high doses in hospitals to treat or prevent the respiratory illness. However, recent pilot and observational studies have suggested positive effects. A Queen Mary University of London study recently found that high-dose vitamin D supplementation significantly protects against respiratory illness.’

Read here (The Guardian, Feb 5, 2021)

Habitual use of vitamin D supplements and risk of coronavirus disease 2019 (Covid-19) infection: A prospective study in UK Biobank

Abstract

Background: Previous studies have related vitamin D supplementation to a lower risk of acute respiratory tract infection. Emerging evidence suggests that vitamin D insufficiency is related to a higher risk of coronavirus disease 2019 (COVID-19) infection.

Objectives: We aimed to investigate the prospective association between habitual use of vitamin D supplements and risk of COVID-19 infection, and assess whether such an association differed according to the different levels of circulating and genetically predicted vitamin D.

Methods: This study included 8297 adults who have records of COVID-19 test results from UK Biobank (from 16 March 2020 to 29 June 2020). The use of vitamin D supplements, circulating vitamin D levels, and main covariates were measured at baseline (2006-2010). Genetically predicted vitamin D levels were evaluated by genetic risk score.

Results: After adjustment for covariates, the habitual use of vitamin D supplements was significantly associated with a 34% lower risk of COVID-19 infection (OR, 0.66; 95% CI, 0.45-0.97; P = 0.034). Circulating vitamin D levels at baseline or genetically predicted vitamin D levels were not associated with the risk of COVID-19 infection. The association between the use of vitamin D supplements and the risk of COVID-19 infection did not vary according to the different levels of circulating or genetically predicted vitamin D (P-interactions = 0.75 and 0.74, respectively).

Conclusions: Our findings suggest that habitual use of vitamin D supplements is related to a lower risk of COVID-19 infection, although we cannot rule out the possibility that the inverse association is due to residual confounding or selection bias. Further clinical trials are needed to verify these results.

Read here (American Journal of Clinical Nutrition, Jan 29, 2021)

Vitamin D and Covid-19: Why the controversy?

‘The issue of vitamin D supplementation has been extensively debated, with strong arguments in favour and against. The COVID-19 pandemic has further escalated the discussion. It has long been clear that groups that traditionally exhibit vitamin D deficiency or insufficiency, such as older adults and nursing home residents, and Black, Asian, and minority ethnic populations, are the same groups that have also been disproportionately impacted by COVID-19. Additionally, increased time spent indoors due to strict lockdowns and shielding triggered concerns that some people might not obtain the necessary physiological levels of vitamin D from sunlight...

‘On Dec 17, 2020, the National Institute for Health and Care Excellence (NICE), in collaboration with Public Health England and the Scientific Advisory Committee on Nutrition, published an updated rapid review of recent studies on vitamin D and COVID-19. Their recommendations support the current government advice, revised in April, 2020, during the first lockdown in the UK, for everyone to take vitamin D supplements to maintain bone and muscle health during the autumn and winter months... However, the rapid review concluded that sufficient evidence to support vitamin D supplementation with the aim of preventing or treating COVID-19 was still lacking and that the topic should be further investigated. Experts studying vitamin D welcomed the call for more research, but the lack of specific recommendations in the context of COVID-19 was also met with disappointment by many in the scientific community who have argued that vitamin D supplementation is generally safe and that any potential low toxicity would likely be strongly outweighed by any potential benefits in relation to protection from COVID-19.

‘NICE should continue to monitor new evidence as it is peer-reviewed and published, including results from several clinical trials on vitamin D and COVID-19 outcomes that are currently underway. However, particularly in countries where the pandemic situation continues to worsen (and will continue to do so during the winter months before the effects of vaccinations become perceptible), additional evidence could come in just too late. In an ideal world, all health decisions would be made based on overwhelming evidence, but a time of crisis may call for a slightly different set of rules.’ [blog editor’s emphasis]

Read here (The Lancet, Jan 11, 2021)

Vitamin D may help in Covid-19 fight, studies show

‘Multiple studies suggest that having adequate amounts of vitamin D may play a role in helping people stave off or combat the coronavirus, although the jury is still out on whether the results are conclusive or why this is so.

‘At least one overseas study has associated vitamin D deficiency with a higher risk of Covid-19. Published in medical journal JAMA Network Open on Sept 3, the study observed 489 patients from the University of Chicago Medicine health system, about a third of whom had vitamin D deficiency. Patients with vitamin D deficiency and who were not given treatment for it were 1.77 times more likely to test positive for Covid-19 than those who were not. The study also noted that other research had found that Covid-19 was less prevalent in groups that had lower rates of vitamin D deficiency.’

Read here (Straits Times, Sept 16, 2020)

The role of vitamin D in reducing risk of COVID-19: A brief survey of the literature

‘The evidence that higher vitamin D status is causally linked to lower risk of COVID-19 incidence, severity, and death continues to increase. This brief report outlines what has been learned through early June 2020 and provides links to some of the key references.

‘It should be noted that acceptance of the role of vitamin D supplementation will probably not be achieved before reports are published that demonstrate randomized controlled trials of vitamin D supplementation significantly reduced COVID-19 incidence or death. Several RCTs and observational studies regarding vitamin D supplementation and COVID-19 incidence and outcomes are either in the planning stage or in progress. The obvious groups to study are those at highest risk: dark-skinned people living at high latitudes, people in nursing homes or health care facilities; prisoners; factory workers such as in meat-packing facilities in the U.S.; health care workers. A major problem is that the powers that be see vitamin D as a threat to income and profit, so use the Disinformation Playbook to suppress positive information on vitamin D...

‘In a review published in early April, it was proposed that vitamin D supplementation could reduce the risk of COVID-19. Two mechanisms were identified: 1, reduced survival and replication of viruses through vitamin D-stimulated release of cathelicidin and defensins, and 2, reduced risk of the cytokine storm by reducing production of pro-inflammatory cytokines...’

Read here (Orthomolecular Medicine News Service, June 9, 2020)

Vitamin-D and Covid-19: Do deficient risk a poorer outcome?

‘A role for vitamin D in the response to COVID-19 infection could be twofold. First, vitamin D supports production of antimicrobial peptides in the respiratory epithelium, thus making infection with the virus and development of COVID-19 symptoms less likely. Second, vitamin D might help to reduce the inflammatory response to infection with SARS-CoV-2. Deregulation of this response, especially of the renin–angiotensin system, is characteristic of COVID-19 and degree of overactivation is associated with poorer prognosis. Vitamin D is known to interact with a protein in this pathway—angiotensin-converting enzyme 2 (ACE2)—which is also exploited by SARS-CoV-2 as an entry receptor. While SARS-CoV-2 downregulates expression of ACE2, vitamin D promotes expression of this gene.’

Read here (The Lancet, May 20, 2020)

Study finds link between low Vitamin D levels in people and higher mortality and higher occurrence of Covid-19; suggests supplementation

Vitamin D has already been shown to protect against acute respiratory infections. This study aimed to assess the association between the mean levels of Vitamin D in people in various countries and (1) the mortality rate of Covid–19 and (2) the number of cases of the disease.

It finds a positive correlation and says: ‘Vitamin D levels are severely low in the ageing population especially in Spain, Italy and Switzerland. This is also the most vulnerable group of population for Covid-19’. It concludes: ‘We advise Vitamin D supplementation to protect against SARS-CoV2 infection’.

Read here (Research Square, April 8, 2020)