The festive period is a much-anticipated period for most people but this Christmas Day was more important for Doctor Who fans than most: after Peter Capaldi’s 12th Doctor regenerated into a woman. Jodie Whittaker became the first female Doctor - and the 13th overall - but one fan in particular was concerned about the regeneration process and wrote to Capaldi to tell him his fears.

Peter CapaldiPeter Capaldi wrote a handwritten note to a concerned nine-year-old super fan

Nine-year-old super fan David McGilloway, from Londonderry, had been "dreading" the regeneration according to his dad Brian but actor Capaldi sent him a note - via Father Christmas - to ease his worries.

Capaldi’s handwritten letter assured McGilloway that while "regenerating is not completely good fun" and "can be a little bit icky (like really bad flu)", it "always, always turned out good for Dr. Who."

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David’s father posted Capaldi’s reply on Twitter yesterday (27 Dec) and praised the way the Thick of It actor had taken the time out to write to his son.

Tweeting a picture of the letter itself, Brian wrote: "#PeterCapaldi is my 9yo son’s fav #DoctorWho and he was dreading his regeneration. And then he got this letter with some words of comfort from the Doctor himself among his Santa presents. Such a kind man.”

Speaking to the BBC, young David said: "The letter was just so magical, the envelope it came in, Peter Capaldi drew a Dalek on it and it said my name on it."

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In the letter, Capaldi also reassured David the old Doctors never really go away, "they are always there in time and space".

He wrote: "It's like the Doctor says, everything ends and it's always sad. But everything begins again, and that's always happy. Be happy.

"So have a brilliant Xmas, a Happy New Year and a wonderful life - I'm sure you will."

Doctor Who was first broadcast in 1963 and had a relaunch in 2005.

Capaldi replaced Matt Smith as the Doctor - whose ability to regenerate has allowed a number of actors to play the role - four years ago.