Vitamin D for Chemoprevention

* Participants will be asked to answer some questions about their diet, exercise and health. In addition, participants blood pressure will be taken. These assessments will occur at baseline, 3- and 6-month appointments. At baseline only, we will measure skin tone with a tool called the Photovolt 577. * A small blood sample will be taken to see how much Vitamin D is the body and will also look at levels of other markers of disease such as proteins, hormones, and genes. * Participants will take a vitamin pill every day for three months and be randomly assigned to one of four different types of pills. * Participants will be called or visited at least every two weeks. They will be asked questions to determine if they have any side effects associated with high levels of Vitamin D. * At the beginning of the second and third months, participants will be provided with more pills. At the end of the third month, another blood sample will be taken. Three months after that, the final blood sample will be taken.