I use full spectrum lights for my parrots, who need it (or actual sunlight, not filtered through glass) for health. I don't know whether it helps with Vitamin D in humans, though.
It is an extraordinarily pleasant light. I use long fluorescent full spectrum lightbulbs that I buy at the hardware store - much cheaper than what is sold in specialty shops, and has the same effectiveness. (I changed ceiling fixtures to accommodate the bulbs.)