The Foxes' hopes of a top-six finish had been hurt by a run of three defeats in four matches but they returned to winning ways in emphatic style thanks Vitor's brace and a third from Kyle Naughton.
Scunthorpe are desperate for points at the other end of the table but, although Joe Garner came close to giving them an early lead, they were second best and remain four points from safety.
The Foxes deservedly took the lead when Paul Gallagher's corner was guided towards the back post by Ben Mee and defender Vitor stabbed in his second goal for the club.
Scunthorpe's challenge was all-but ended in the 72nd minute, though, when a peach of a right-wing cross from Gallagher was headed in off the crossbar by Vitor.
Four minutes later, Leicester had their third as a short free-kick from Gallagher caught out the home defence, allowing Naughton to curl in a precise shot.
Source: PA
Source: PA