Multiple studies have suggested that vitamin D could prevent COVID-19 infections--or at least reduce the severity of the novel coronavirus's symptoms.br But according to Business Insider, new research says patients with severe COVID-19 don't seem to benefit from taking large doses of vitamin D.br Researchers from the University of Sao Paolo, Brazil, looked at 240 Brazilian patients hospitalized with severe COVID-19 between June and October.br Half received a single large dose of 200,000 IU of vitamin D3; the other half received a placebo.br The dose in this study, 200,000 IU, is 500 times the recommended daily amount of vitamin D, significantly more than most people would take on a regular basis.br The vitamin D recipients showed no greater improvements than the placebo group. They were just as likely to need intensive care, ventilator treatment, or die of their illness.