.@ScottAdamsSays Somebody will send you this link that seems to suggest Vitamin D reduces COVID-19 mortality. Allow me to explain why this is a complete fraud paper with no actual results and why @amanda_mo @NorthwesternU shouldn't promote it. medicalxpress.com/news/2020-05-v…
I've actually read the non-peer-reviewed preprint (medrxiv.org/content/10.110…). Paper and post on @medical_xpress suggest the researchers use patient data from various countries and find that lower Vitamin D is linked to lower mortality. That's not true: They don't use patient data.
The paper is so terrible to read because they are never clear about what they do. They seem to just correlate COVID-19 fatality rates with Vitamin D levels of the population at the country(!) level, so they have like 9 observations. Also they don't seem to control for any other
variables, no comorbidities, nothing. They also don't report a table of their estimates or their statistical significance. Then they claim (without grounds) that normal Vitamin D levels reduce the risk of severe COVID-19 by 15.6% compared to severe Vitamin D deficiency.
Funny part: One of the authors, a Vadim Backman, says: "Our analysis shows that it [effect of Vitamin D] might be as high as cutting the mortality rate in half" - that's not even supported by their own paper. So even their claims about their fraud paper are fraud.
That's why I'm sceptical regarding questions about the potential effect of variable X. There are so many fraudulent papers out there by now that are able to avoid scientific rigor and raise false - or at least unsubstantiated - hopes that they will receive coverage nevertheless.
