You shouldn’t be surprised at this at all. There is zero profit motive for the amount of money it would take to do a vitamin D trial since no one can patent vitamin D.
I always feel like the people who make these sort of comments have never actually read a medical journal.
A huge amount of study does not lead to patentable medication, but is either performed by research groups, or is performed as part of R&D of another products and then published in papers.
I have been reading medical journals for 12 years and I have collaborated on a study that is looking into manganese transport and/or deficiency as a possible cause of ME/CFS and Long Covid.
There is a difference between something that could never be patented (Vitamins), and the possibility of something working becoming patented (Prozac for example).
The first does not get the funding but from benefactors, as in the case of the study I collaborated with.
