I can't believe this has been spun as just the "Internet generation". Vitamin D deficiency affects almost everyone, not just "kids on that damn Internet!" Most of us work inside, spend our leisure time inside, wear sunscreen when outside, etc.
Yes, I've recently become a vitamin D convert and have learned quite a bit about it through William Davis' Heart Scan Blog: http://heartscanblog.blogspot.com/
It turns out that as you age, your ability to absorb vitamin D through sunlight decreases, so past 40, you probably need supplementation.
I simultaneously did two things starting Jan 1: I stopped eating wheat and started taking vitamin D. Although I can't pinpoint which of these is the determining factor, I can report that I have much more energy (no post lunch drag, nor desire to nap after work) as a result. I also seem to sleep better. Check out:
I take 4,000-6,000 UI of Vitamin D3 daily in gelcap/softgel format (Vit D is fat soluble, the dry tablets aren't absorbed nearly as well, which has been confirmed by blood tests).
It costs almost nothing. A bottle of 360 softgels each containing 2,000 UI costs about $25 (Carlson Laboratories brand).
Just curious if you've noticed any difference in your health since taking the Vitamin D supplement?
For comparison that's about how much Vitamin D your skin will produce by being in the sun for 5-10 minutes (assuming you're in normal latitudes and have uncovered face, hands, arms - not always true in the winter).
"Some consumers and doctors are becoming convinced vitamin D can help reduce the risk of a long list of diseases, despite a lack of gold-standard research proving it."