The first double blind parallel randomised study to vitamin D with a good design is out, prevents 75% of infections, so way better than the vaccination!
It exactly confirms my point that the vitamin D addition to many food products in Taiwan is the real reason how Taiwan could avoid covid for so long and why it will be here like in Norway:
And yeah while the virus of course can adapt to vaccines, it most likely cannot adapt to better immune system by vitamin D.
Now sadly Taiwan is not supplementing around 4000 IU per day but rather 1500. But that explains perfectly why it could stop pre Delta, had a hard time with Delta and is now not possible to stop omicron. Assuming marginal gains on increasing supplementation 1500 IU will halve the infectibility. With an R of 2-3 for Delta that worked and with 4000 IU most likely Delta could not even spread without any other protective measures. As it developed to omicron it’s not enough. But it will very surely prevent a lot of severe disease as shown in other studies.
Remember Taiwan and Norway have the highest vitamin D serum levels of any country worldwide.