Yes this is right, the most widely used player is harmful for laptops because it boosts its sound upto 200-400%.
laptop can only hold upto 100% ,so if your laptop is new ,than use another video player or if u really want to use this player no matter what ,than u should only use 100% volume of vlc player than it will not affect your laptop speakers.
Remember that the bar of vlc volume control should not cross 100% , you can than keep your laptop volume to 100%.
See the pic for more understanding of this topic.
What vlc player does is that they amplify sound to 200% making you to listen louder, other music software have their amplification rate as well. Old version of vlc player amplifies to 400% but latest version has decreased it to 200%. Some laptop manufacturing companies also tell its user that they are against vlc player because it destroys their speakers quality.
So its better option to use microphone instead of playing movies at 200% rate.