This film publicity image released by Sony Pictures shows the movie poster for Michael Jackson’s “This is It” film.

New York ? Kenny Ortega was responsible for some of Michael Jackson’s biggest concerts, including what were to be his comeback shows in London. But in the singer’s final days, the producer-director-choreographer felt like he needed to take on another responsibility — making sure Jackson stayed healthy.

“Michael had sleepless nights and we had to look after him. (I’d say to him), ‘Stay hydrated, have a protein shake — Did you eat today before you came?”‘ Ortega said in an interview Thursday to promote the new Jackson documentary, “This Is It.”

“Michael’s an adult. … We didn’t want to baby him,” he said. “(But) I had concerns and we had conversations, wanting to make sure he was doing everything he could to build himself and not break himself down.”

Jackson died June 25 at age 50. The Los Angeles County coroner has ruled Jackson’s death a homicide, caused primarily by the powerful anesthetic propofol and another sedative. Jackson’s personal physician, Dr. Conrad Murray, has not been charged with a crime but is the focus of the police investigation.

Ortega’s work with Jackson included world tours for Jackson’s “Dangerous” and “HIStory” albums. He was directing the “This Is It” shows — which would have marked the performer’s comeback concerts in London’s O2 Arena in July — and was brought on to direct a film adaptation of those taped rehearsals after Jackson’s death.

“This Is It” will premiere globally on Tuesday and run for two weeks. The soundtrack for the film, which includes the newly released title track as well as some of his best-known hits, is being released today.

In a 12-minute clip previewed for media on Thursday, a strong-voiced King of Pop is shown practicing some of his biggest hits.

Jackson, though frail-looking, is shown warming up his vocals during a performance of “Human Nature.” Then he runs through the song in various outfits. Later, he playfully dances with a woman as he sings “The Way You Make Me Feel.”

Ortega says although he worried about Jackson’s health, he doesn’t believe the preparation for the shows wore the singer down. In fact, he says it was the opposite.

“I can tell you this experience, working on this show, was invigorating, was nourishing. … (it) wasn’t taking away from Michael,” he said.

Travis Payne, a choreographer who worked on “This Is It” and other Jackson tours, says he remembers spending one-on-one time with Jackson — especially visiting Web sites like YouTube.

Musical director Michael Bearden recalls Jackson’s lofty goal to try to capture all of his music in one, over-the-top show. “He had so, so much music that we tried to get everything in but not cheat the audience at the same time,” he said.

Ortega says Jackson was very adamant about the look of the tour — from the length of the songs to the stage’s lighting.

“That’s what ‘This Is It,’ Michael Jackson’s ‘This Is It’ the film, is about — it’s a privileged peek into the final creative process of Michael’s last theatrical work,” he said.