In a comment reported in The Lancet, Adrian R Martineau and Nita G Forouhi observe:
“The striking overlap between risk factors for severe COVID-19 and vitamin D deficiency, including obesity, older age, and Black or Asian ethnic origin, has led some researchers to hypothesise that vitamin D supplementation could hold promise as a preventive or therapeutic agent for COVID-19.”
…
“Two ecological studies have reported inverse correlations between national estimates
of vitamin D status and COVID-19 incidence and mortality in European countries.4,5 Lower circulating 25(OH)D concentrations have also been reported to associate with susceptibility to SARS-CoV-2 infection6 and COVID-19 severity. Recently, we have shown that airway diseases are associated with dysregulated vitamin D metabolism, raising the possibility that vitamin D deficiency might arise as a consequence of pulmonary inflammation.”
After reviewing the literature and trials to date, they observe:
“Pending results of such trials, it would seem uncontroversial to enthusiastically promote efforts to achieve reference nutrient intakes of vitamin D, which range from 400 IU/day in the UK to 600–800 IU/day in the USA. These are predicated on benefits of vitamin D
for bone and muscle health, but there is a chance that their implementation might also reduce the impact of COVID-19 in populations where vitamin D deficiency
is prevalent; there is nothing to lose from their implementation, and potentially much to gain.”
Indeed
https://www.sciencedirect.com/science/article/pii/S2213858720302680
Econophysics2020 