Evidence of Vitamin D fighting COVID-19 etc. - take 4,000 IU if less than 20 ng (UK) – Dec 1, 2020

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

Royal Society - Open Science: 01 December 2020https://doi.org/10.1098/rsos.201912
George Griffin, Martin Hewison, Julian Hopkin, Rose Kenny, Richard Quinton, Jonathan Rhodes, Sreedhar Subramanian and David Thickett


70% of the Vitamin D and COVID-19 Clinical Trials use 100,000 IU in the first week.
   This study suggests 28,000 IU if <25 nmol, otherwise 7,000 IU
Many researchers suggest a target goal of >100 nmol,
   This UK study has a target of 50 nmol
Why has the UK target not recovered from Vitamin D scare/mistake in the 1950s?

COVID-19 treated by Vitamin D - studies, reports, videos

As of Aug 22, 2023, the VitaminDWiki COVID page had:  19 trial results,   37 meta-analyses and reviews,   Mortality studies   see related:   Governments,   HealthProblems,   Hospitals,  Dark Skins,   All 26 COVID risk factors are associated with low Vit D,   Fight COVID-19 with 50K Vit D weekly   Vaccines   Take lots of Vitamin D at first signs of COVID   166 COVID Clinical Trials using Vitamin D (Aug 2023)   Prevent a COVID death: 9 dollars of Vitamin D or 900,000 dollars of vaccine - Aug 2023
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 Download the PDF from VitaminDWiki

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.


  • 1. Vitamin D is a hormone that regulates many genes and is dependent on ultraviolet (B) skin exposure for its generation
  • 2. People with dark skin, who are obese, who are elderly or who are institutionalized are more likely to be vitamin D deficient
  • 3. Vitamin D deficiency may impact the risk of respiratory viral infection
  • 4. A molecular and cellular explanation of how vitamin D sufficiency may protect against COVID-19
  • 5. Latitude associations with COVID-19 mortality imply seasonality and a plausible link with vitamin D
  • 6. Preliminary evidence of associations between vitamin D status and COVID-19
  • 7. Randomized controlled trials of supplementary vitamin D in COVID-19
  • 8. Identifying the appropriate vitamin D target blood levels and supplement dosing
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