All of arthole's Comments + Replies

Re: SAD. you may want to consider that SAD is a side-effect of a decay or change of molecules in the body produced by sunlight. Skin exposed to sunlight produces D3, because of a UVB reaction in skin cells. The lack of available D3 in her blood stream, and thus her brain may be the physical component producing the psychological phenomena of SAD.

2ChristianKl
This is obvious advice. In this case I think it's relatively unlikely that Brienne doesn't take D3 supplements or tested herself, but I don't think there a reason to downvote people for writing obvious advice.