so it was more of a lab burn? This sounds like a great study, I wonder what the participants were asked… “Come participate, will give you sunburn for $$$.
That is one way to start a conversation, haha.
I realize this was a double blind clinical trial but the results are intriguing.
Do you have any thoughts on why the gene expression of the non-responders was different than the responders group?
Genetic variations leading to a differing response to vitamin D supplementation is a previously identified phenomenon.
https://www.ncbi.nlm.nih.gov/pubmed/23935129
So that part isn't surprising, however as to why this genetic difference occurs between people? That I don't know. More information is probably out there in the literature that sheds some light on it somewhere. I haven't looked though.