WebMD editor Dr. Michael Smith and CBS News medical correspondent Dr. Jon LaPook answer a Twitter question about the importance of Vitamin D and its role in cancer prevention.
Latest U.S. Headlines - CBS News, CBS News: Nation
Thu, 12/09/2010 - 4:09pm
WebMD editor Dr. Michael Smith and CBS News medical correspondent Dr. Jon LaPook answer a Twitter question about the importance of Vitamin D and its role in cancer prevention.