Vitamin D and COVID-19: evidence and recommendations for supplementation

Abstract

Vitamin D is a hormone that acts on many genes expressed by immune cells. Evidence linking vitamin D deficiency with COVID-19 severity is circumstantial but considerable—links with ethnicity, obesity, institutionalization; latitude and ultraviolet exposure; increased lung damage in experimental models; associations with COVID-19 severity in hospitalized patients. Vitamin D deficiency is common but readily preventable by supplementation that is very safe and cheap. A target blood level of at least 50 nmol l −1 , as indicated by the US National Academy of Medicine and by the European Food Safety Authority, is supported by evidence. This would require supplementation with 800 IU/day (not 400 IU/day as currently recommended in UK) to bring most people up to target. Randomized placebo-controlled trials of vitamin D in the community are unlikely to complete until spring 2021—although we note the positive results from Spain of a randomized trial of 25-hydroxyvitamin D3 (25(OH)D3 or calcifediol) in hospitalized patients. We urge UK and other governments to recommend vitamin D supplementation at 800–1000 IU/day for all, making it clear that this is to help optimize immune health and not solely for bone and muscle health. This should be mandated for prescription in care homes, prisons and other institutions where people are likely to have been indoors for much of the summer. Adults likely to be deficient should consider taking a higher dose, e.g. 4000 IU/day for the first four weeks before reducing to 800 IU–1000 IU/day. People admitted to the hospital with COVID-19 should have their vitamin D status checked and/or supplemented and consideration should be given to testing high-dose calcifediol in the RECOVERY trial. We feel this should be pursued with great urgency. Vitamin D levels in the UK will be falling from October onwards as we head into winter. There seems nothing to lose and potentially much to gain.

Perspective: Vitamin D supplementation prevents rickets and acute respiratory infections when given as daily maintenance but not as intermittent bolus: implications for COVID-19

“…Controversy surrounding the possible benefits from taking vitamin D supplements has become more prominent recently with the reports of various associations between vitamin D deficiency and risk of COVID-19. 1 Authorities have given only muted support to avoidance of vitamin D deficiency during the current COVID-19 pandemic, concluding that there is insufficient evidence from randomised trials of supplementation to support any protective effect against COVID-19. 2 Many randomised trials of vitamin D supplementation have been performed in a wide range of conditions with contradictory and often negative results that have led to considerable scepticism about its value.…”

“…We have pointed out elsewhere the links between vitamin D deficiency, latitude, seasonality, ultraviolet exposure, obesity, ethnicity and COVID-19 risk. 1 There, and elsewhere, 36 we have also discussed the complex impacts of illness on interpretation of circulating 25(OH)D concentrations in sick patients, the possibility of the 'healthy user' effect and the difficulties these present in drawing firm conclusions from association data. Nevertheless, the marked congruence between the risk factors for vitamin D deficiency and the risk factors for severe COVID-19 make the link very plausible.…”

COVID 19 – Possible interrelations with respiratory comorbidities caused by occupational exposure to various hazardous bioaerosols. Part II. Clinical course, diagnostics, treatment and prevention

“…In the elderly, there was also observed vitamin D deficiency, which increases the risk of severe COVID-19 and guts microbiota dysbiosis [74]. According to Griffin et al [20], vitamin D deficiency in European countries significantly correlates with mortality per million from COVID-19. Thus, the authors urge European governments to recommend vitamin D supplementation at 800-1,000 IU/ day for all citizens [20].…”

“…According to Griffin et al [20], vitamin D deficiency in European countries significantly correlates with mortality per million from COVID-19. Thus, the authors urge European governments to recommend vitamin D supplementation at 800-1,000 IU/ day for all citizens [20]. Vodnar et al [18] recommend that people at a higher risk (older and chronic disease-affected individuals) must abstain from unhealthy eating habits and should try to consume more unprocessed food, whole grains, vegetables, and unsaturated fats, to boost the immune system and induce protection against viral infections.…”

“…Until recently, there did not exist a single globallyaccepted treatment for COVID-19 [12,13,14,15]. Among the applied therapeutics, the most common are: antiviral drugs (such as Remdesivir), anti-inflammatory drugs (such as corticosteroids), immunomodulators (such as interferons, monoclonal antibodies, convalescent plasma), and supportive therapy such as supplementation of the diet with probiotics, prebiotics, vitamins and microelements, which deserve a special attention [1,3,16,17,18,19,20].…”