On: Lack of sunlight makes our cells store more fat (2...

[ineedasername]

Is that because it's closer to the skin, or changes the refractive properties? (or both?)

[amelius → ineedasername]

Closeness doesn't matter, I suppose. Make a t-shirt partially wet, hold it in front of some light source and you will see that the wet parts are much brighter. This will probably be the case too for UV light.