The Vampire Diaries was a series of novels in the 1990s by some mortal woman named L.J. Smith. Vidar did not read these books. This Young Adult genre has never really piqued Vidar’s interest. Vidar hasn’t even read The Prose and Elder Edda by Snorri Sturlson and Vidar is featured prominently in those works. Vidar is a voracious reader but mostly non-fiction.
Here is detailed information from Wikipedia:
The Vampire Diaries is a YA horror series of novels written by the NYT Bestselling author of the Night World series, L.J. Smith. The story centers around Elena Gilbert, a high school girl torn between two vampire brothers. The series was originally a trilogy published in 1991.However, pressure from readers led the author to write a fourth volume, Dark Reunion, released in 1992.
After taking a hiatus from writing for several years, L.J. Smith announced in 2008 a new spin-off trilogy entitled The Vampire Diaries: The Return, continuing the series, with Damon being the main protagonist. The first installment, The Return: Nightfall, was released on February 10, 2009. The Return: Shadow Souls and The Return: Midnight are tentatively slated for release in April, 2010 and 2011 respectively.