Vitamin D supplementation neither protects against SARS-CoV-2 infection nor reduces the severity of COVID-19, two clinical trials suggest, contradicting a hypothesis that arose early in the pandemic.
The studies were launched in 2020 based on previous findings that vitamin D seems to boost the immune system. Queen Mary University researcher David Martineau, a coinvestigator of one of the clinical trials, told The Scientist at the time that he hoped the results would carry over to the coronavirus that had only recently swept the globe. But the results of the trials, both published Wednesday (September 7) in BMJ, may put that idea to rest.
One of them, which ran from November 2020 to June 2021 and included 34,601 adult participants from Norway, tested a low dose of vitamin D (in the form of a cod liver oil supplement) and did not find any association between supplementation and the number of SARS-CoV-2 ...





















