Yes. There's a ton. Most of it is horribly tainted by correlation effects. Let's consider one of the studies you cited above, which is an observational study from the VA hospitals:
"In the population of US veterans, we show that Vitamin D2 and D3 fills were associated with reductions in COVID-19 infection of 28% and 20%, respectively"
This sounds really awesome, right? Except -- you could also interpret this as "People who are following their doctor's recommendations, going to the pharmacy to fill their prescriptions, and taking them, do better". No kidding - they're probably also taking their other medications and being more generally medically careful!
This is completely consistent with the 99% of vitamin d-related results that show that it correlates with all sorts of positive outcomes.
The high quality interventional studies -- which are actually potentially able to demonstrate causality -- are generally negative. And the larger and better they are, the more likely they are to be negative. One of the largest was the CORONAVIT trial; it was, unfortunately, open-label, but it was large and randomized. (Note that you'd expect the open-label aspect to result in a stronger placebo effect, which .. well, given that they found no benefits, did not occur). https://www.bmj.com/content/378/bmj-2022-071230
The vitamin d & covid horse is pretty dead at this point, which is basically the same as the "vitamin d & x" horse for most values of X other than diseases known to be directly caused by vitamin D deficiency. Which are serious and worthy of treatment. Just don't expect vitamin D to be a miracle cure on the basis of its correlation with everything positive.
"In the population of US veterans, we show that Vitamin D2 and D3 fills were associated with reductions in COVID-19 infection of 28% and 20%, respectively"
This sounds really awesome, right? Except -- you could also interpret this as "People who are following their doctor's recommendations, going to the pharmacy to fill their prescriptions, and taking them, do better". No kidding - they're probably also taking their other medications and being more generally medically careful!
This is completely consistent with the 99% of vitamin d-related results that show that it correlates with all sorts of positive outcomes.
The high quality interventional studies -- which are actually potentially able to demonstrate causality -- are generally negative. And the larger and better they are, the more likely they are to be negative. One of the largest was the CORONAVIT trial; it was, unfortunately, open-label, but it was large and randomized. (Note that you'd expect the open-label aspect to result in a stronger placebo effect, which .. well, given that they found no benefits, did not occur). https://www.bmj.com/content/378/bmj-2022-071230
The vitamin d & covid horse is pretty dead at this point, which is basically the same as the "vitamin d & x" horse for most values of X other than diseases known to be directly caused by vitamin D deficiency. Which are serious and worthy of treatment. Just don't expect vitamin D to be a miracle cure on the basis of its correlation with everything positive.