Colorectal Cancer connection with Vitamin D

Hello All.  I just got out of my Physiology class and we talked about the connection between Colorectal cancer and Vitamin D and I thought I would share it with you guys.  Our bodies can't process Vitamin D, which is stored in the cells in our skin.  Once sun light (UV rays) react with the Vitamin D it turns it into Vitamin D2.  It then travels to our liver or kidneys (I can't recall which one at the moment) and it turns it into Vitamin D3 which our body can then process.  People that live in higher altitudes have a greater risk of colorectal cancer because they do not get a lot of sunlight.  My professor proceeded to tell us not to run to the tanning beds during the winter for two reasons.  1.  Vitamin D3 stays in our bodies for three months 2.  Skin cancer is worse then colorectal cancer.