Boosting your immunity system claims, always seem to be an easy way to part fools with their money. In this instance a combination of Vitamin D, C Zinc and Magnesium, looks like a good bet, along with good sleep. However anyone one blood thinners need to check that any supplements don't...
Sorry to nitpick, there is plenty of evidence to support it, which is why there is a lot of work kicking off to better understand the links and the significance. There are though no definitive conclusions yet either way, which is what I think you meant.
A quick selection from google news...
Amongst the death stats obsessives (yes I am included here) there has been a lot of debate around the accurate recording of cause of death.
The virus has been tightly linked to pneumonia/respiratory problems, but there is now growing evidence that Covid-19 may be responsible for blood clotting...