This link will take you to an article and video. The article explains the difference between UVA and UVB, as well as the effects of optimizing vitamin D levels. In the video, a breast cancer survivor, who has been well-educated in science, explains studies of the importance and value of vitamin D. She references pills and tanning in this session.
http://www.agoracosmopolitan.com/news/health/2012/01/04/2559.html
