> Although this is a notable finding it's important to remember that it doesn't lead to the conclusion that supplementing vitamin D will be very beneficial here....we don't have a ton of good science to back up if curing a vitamin D deficiency via supplementation of pure vitamin D is really nearly the same as getting it naturally

I don't know what you mean by 'a ton', but there is good evidence that Vitamin D supplements do provide much of the same benefit [0] [1].

> Ultraviolet radiation (either from artificial sources or from sunlight) reduces the incidence of viral respiratory infections, as does cod liver oil (which contains vitamin D).

[0] https://pubmed.ncbi.nlm.nih.gov/16959053/

[1] https://sci-hub.se/https://www.sciencedirect.com/science/art...