> why are we not informed

What do you mean? I've been bombarded with Vitamin D recommendations since COVID started, from my doctor through countless podcasts. It also comes up frequently in any online discussion about COVID. And before anyone suggests otherwise, yes, Dr. Fauci has also spoken about Vitamin D.

But Vitamin D isn't a magic bullet. It helps, but it's not a miracle cure like some of the internet articles or early ad-hoc studies would imply.