If there were a gold medal for good fortune, Nicholas Sparks would be standing atop the podium. The 44-year-old husband and father of five from North Carolina writes tear-jerking romances that have sold more than 50 million copies in more than 30 languages. Six of his 15 books have been made into movies that attract devoted female fans.

One of those admirers is teen singing sensation Miley Cyrus, who was looking to transition from her TV career when her representatives approached Sparks at a fortuitous time.

“I had just finished writing ‘The Lucky One,’ and I was fishing around for a new story,” he said in a recent phone interview from a Los Angeles junket. “What I always try to do is make my next novel as different as possible from the last one. One of the main ways I do that is to vary the ages of the characters, because different ages bring different dilemmas. If the main characters are in their 40s, there might be kids involved; if they’re 80 years old, they’ve had a whole lifetime together.

“In my previous three books, including ‘Nights in Rodanthe,’ I had done characters from 20 to 50, so I thought I would write about a teenager, because I hadn’t done that since ‘A Walk to Remember.’ And since that book was about a boy, I had decided to write about a girl. Then coincidentally, that’s when they called and asked if I had something that might be good for Miley. And I said ‘Funny you should mention that.’ “

Sparks presented the idea for his next novel to Miley and her father, Billy Ray Cyrus. They loved the idea of a story about a rebellious girl making peace with her estranged father.

“But they asked me to write the screenplay first, so they could start production as soon as possible,” Sparks said. “I had never written a screenplay before, but I said sure. It made no difference to me.”

The result was “The Last Song,” which opened last week, starring Miley Cyrus and Greg Kinnear.

Sparks, who majored in business at Notre Dame, takes a practical approach to his work.

“I have deadlines,” he said. “I don’t like them at all, but I’d probably be bored if I wasn’t writing, so a novel a year is a fairly reasonable pace.”

Pace is a good word to apply to Sparks, who was a track star in college and still runs every day. After graduation, his first published book was a biography of American Indian runner Billy Mills. Sparks worked in pharmaceutical sales while he polished his early novels. One of them, “The Notebook,” was plucked from a pile of unsolicited manuscripts in 1995 by a literary agent who thought it had commercial potential.

She was right.

The book drew a million-dollar advance from Time-Warner, whose New Line division would turn the best-seller into a hit movie in 2004. More books and movies followed, including “Nights in Rodanthe” and “Dear John.”

Sparks says his books are well-suited for movie adaptations.

“In my novels, there are generally two main characters, limited settings and a simple story line,” he said. “If you’re going to turn a thousand-page Tom Clancy novel into a movie, you’re going to have to cut out 90 percent of the book. With mine, you can capture most of what’s on the page.

“I’ve had a fortunate run, with no clunkers yet. I do pick the producers carefully. If I don’t like them, I don’t sell the project to them. What I ask them to do is retain the overall spirit of the characters and story and then make the best movie they can. You don’t want to turn Noah Calhoun from ‘The Notebook’ into a raging alcoholic wife-beater because you think it will add drama to the film. There’s already enough drama in daily-life situations.”

Sparks, whose mother and father were killed in a horse-riding and car accident, respectively, accepts that he has a reputation for writing sad stories.

“I am driven by the essential belief that if you have a love story, all great loves, by definition, are marked by tragedy,” he said. “That’s because death is inevitable. What happens after that, we’ll have to wait and see.”