Dr. Mehmet Oz, the celebrity TV host, vigorously defended the medical advice he dispenses on his show, striking back on Thursday against physicians who called his faculty position at Columbia University “unacceptable” in an email to the school last week.

During an episode of his syndicated daytime talk program, “The Dr. Oz Show,” that was broadcast on Thursday, Dr. Oz said his critics were attacking his freedom of speech.

“I vow to you right here and right now, we will not be silenced,” he said.

Dr. Oz, who is the vice chairman of Columbia’s surgery department, also defended the advice he shares on his show.

“My life’s work has been built around one simple message: You have a right and a responsibility to become a world expert on your own body,” he said during the show, which was taped Tuesday. “And the way you do that is by having access to the best, most current information; multiple points of view; and diverse opinions.”