Show HN: Vitamin D may reduce susceptibility to Covid-19-associated lung injury

Wow this article is very biased and makes extremely strong claims without sufficient evidence. Readers should be warned that the views expressed by the author are not an accurate representation of the scientific consensus on vitamin d.

Numerous studies have investigated the role of vitamin d supplementation on a wide range of ailments. For example, there was a study looking at whether vitamin d reduced the risk of hip fracture in elderly patients (it doesn't), and another on whether it has any effect on stroke or cardiovascular function (possibly protective against cardiac arrest, not likely against stroke).

The author of this article cherry picked some large studies which found no effect on some particular ailments and then concluded that this is proof vitamin d supplementation is a catastrophic failure.

When you make claims like this, you need to be careful to survey many studies, look at the specific goals the researchers were trying to study, and refrain from making absurdly broad generalizations.