There is an urgent need to understand risk factors for contracting COVID-19 infection and for poorer prognosis thereafter.
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COVID-19 appears to disproportionately affects black and minority ethnic individuals. The underlying mechanism is unknown.
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One potential mediator could be their higher prevalence of apparent vitamin D deficiency.
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We explored whether blood 25 hydroxyvitamin D (25(OH)D) concentration was associated with COVID-19 risk.
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We found no evidence that (25(OH)D) explains susceptibility to COVID-19 infection, either overall or between ethnic groups.
Abstract
Background and aims
COVID-19 and low levels of vitamin D appear to disproportionately affect black and minority ethnic individuals. We aimed to establish whether blood 25-hydroxyvitamin D (25(OH)D) concentration was associated with COVID-19 risk, and whether it explained the higher incidence of COVID-19 in black and South Asian people.
Methods
UK Biobank recruited 502,624 participants aged 37–73 years between 2006 and 2010. Baseline exposure data, including 25(OH)D concentration and ethnicity, were linked to COVID-19 test results. Univariable and multivariable logistic regression analyses were performed for the association between 25(OH)D and confirmed COVID-19, and the association between ethnicity and both 25(OH)D and COVID-19.
Results
Complete data were available for 348,598 UK Biobank participants. Of these, 449 had confirmed COVID-19 infection. Vitamin D was associated with COVID-19 infection univariably (OR = 0.99; 95% CI 0.99–0.999; p = 0.013), but not after adjustment for confounders (OR = 1.00; 95% CI = 0.998–1.01; p = 0.208). Ethnicity was associated with COVID-19 infection univariably (blacks versus whites OR = 5.32, 95% CI = 3.68–7.70, p-value<0.001; South Asians versus whites OR = 2.65, 95% CI = 1.65–4.25, p-value<0.001). Adjustment for 25(OH)D concentration made little difference to the magnitude of the association.
Conclusions
Our findings do not support a potential link between vitamin D concentrations and risk of COVID-19 infection, nor that vitamin D concentration may explain ethnic differences in COVID-19 infection.
