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HELIN LOIK-TOMSON
A few years back, respiratory physician Adrian Martineau of Queen Mary University of London and colleagues analyzed data from about 11,000 participants in 25 trials that tested the effect of vitamin D supplementation on the risk of contracting an acute respiratory tract infection such as influenza. They determined that taking a daily or weekly dose of vitamin D was protective against infections and safe overall. People with the lowest starting vitamin D levels benefitted the most from supplementation.
When David Meltzer, an internist and economist at the University of Chicago, saw that analysis earlier this year, he decided to look into a possible connection between vitamin D and COVID-19. There was good reason to do so. Groups who are often low in vitamin D—such as African Americans, who tend to have darker skin in which higher melanin levels limit UV rays from fueling vitamin D production, ...
