While campaigning this past week, Senator JD Vance of Ohio called Vice President Kamala Harris a “phony” who “grew up in Canada,” as former President Donald J. Trump, the Republican presidential nominee, continued raising false and incendiary questions about the presumed Democratic nominee’s racial identity.

“Kamala Harris grew up in Canada,” Mr. Vance said during a campaign stop in Arizona on Wednesday. “They don’t talk like that in Vancouver or Quebec or wherever she came from.”

Ms. Harris did, indeed, move to Montreal as a 12-year-old with her sister in 1976, when their mother, Shyamala Gopalan, was recruited to conduct breast-cancer research at Jewish General Hospital and to teach at McGill University’s medical school.

Over the next five years, Kamala Harris continued to shuttle between Quebec’s largest city and California to stay with her father, Donald J. Harris, an economist at Stanford, and a family friend during holidays and vacations.

In her memoir, Ms. Harris characterizes that period of her life as a time of longing for California. (Her campaign declined to comment on Ms. Harris’s time in Canada.)

“I’d gotten used to most of it,” she wrote of her move to a predominantly French-speaking city with harsh winters that was far away from most of her family. “What I hadn’t got used to was the feeling of being homesick for my country. I felt this constant sense of yearning to be back home.”