Vitamin D and Sunshine

In Yogaland, we love our sunlight. Or some kind of substitute. One friend and fellow volunteer sits in front of a lap that simulates a clear blue sky into your eye. If exposed indirectly at rougly the same time every day it will make you happier. Another friend practices in front of a sun lamp. I take Vitamin D every morning and dance or sit in the sun whenever possible. Does it make me happier? Maybe.
Would getting much more sunlight make me any happier? Maybe also, and I would think so.
Or would just the idea that such a need is being satisfied in it of itself make me happy? And if that is the case which is actually totally OK with me, it seems like kind of an empty answer to the 'what are we here for?' question.
It feels as though pursuing a spiritual lifestyle, I am feeling more and more called to one everyday, means not getting more sunlight, but figuring out what it is about the lack of sunlight that is effecting you in such a powerful way. I suppose the idea really is to see that every experience is a passing, fleeting moment and that holding onto those moments in any way is the source of all suffering. Daniel said that and it feels right. And at the same time I'm halted at even to begin to conceive that idea. How do you let go of your every day reality and experience and begin to see it as nothing more than a fleeting, ever impermanent entity unto itself? Meditation?
It feels like there's something there. My sits have been getting much smoother, easier to handle the time, to come back to my breath. With exception of today. I kept lightly nodding off. I can imagine that to someone watching without a sense of what was happening, would surely have thought I had the junky nod-off. But that's OK too, especially since I'm going to Daniel's hour sit tonight. I haven't sat an hour yet, but it isn't so scary of a prospect. I just do what I normally do for 45 minutes, a little bit longer. Piece of gluten-free carrot cake, eh?