Dr. Oz celebrates his 48th birthday in the studio with his wife, Lisa, and his producers and takes calls from family and longtime friends. Among the callers are two of his college roommates—Tommy D'Amico, now the chief of cardiovascular and thoracic surgery at Duke University Medical Center, and Billy Campbell, former president of Discovery Networks.

Other well-wishers include friends John Mack, chairman at Morgan Stanley, and his wife, Christy, a philanthropist and president of the Bravewell Collaborative. Author David Kuo also chimes in: "Happy birthday, and thanks for all you do for so many people."

Dr. Oz's mother sends her birthday wishes from Istanbul, and his daughter Daphne takes time out from her European trip to wish her dad a happy birthday.