ISO trouble with the Nikon D5300?

I recently got a Nikon d5300 and i think there's something wrong. I want to shoot video with it and when I go to change the ISO settings it makes no change to my video.

I don't think Nikon emulates settings changes in live view, what does the actual video look like later?

Be sure Auto ISO is turned off.
Be sure to make the ISO adjustment with Live View turned off.

It will have no effect on video that's already been shot.

There's NOTHING wrong with your camera or the video editing program you are using.

It seems that far too many people attempt to shoot video without enough lighting on their set or scene. This will cause the camera to raise the ISO so that you do not get underexposed video.

The same balancing act used by still photographers applies to videographers, ISO, shutter speed and lens aperture

The shutter speed is fixed based upon the frame rate you choose (24 fps-cine, 30 fps-NTSC TV or 60 fps to approximate slow motion)

The only other two factors that determine a good exposure are the lenses maximum aperture and ISO.

Once you have your lens wide open, the last part of this balance is the ISO and it will either automatically increase to provide a good exposure (causing noise) or underexpose the video.

Sadly you do not appear to understand that all your exposure settings have to be done BEFORE you take one second of video. Trying to fix video exposure later in a video editing program is just silly.

You need to take the time to learn the fundamentals of exposure and how it applies to shooting video.

Adjusting ISO only makes the sensor more sensitive to light. It doesn't necessarily make the scene brighter.

Want to make the scene brighter? Use more lights!

Some camera have only "Auto ISO" when shooting video. Check your handbook to see if the D5300 is thus.

If that is the case then obviously you will not be able to set the ISO when shooting video.

That's because as you change the ISO, the camera is changing the aperture. And if you have it in AUTO ISO, it'll automatically change it even after you made changes to the ISO manually.

Just one of the reasons why NOT to use a still camera for video. Get a camcorder and you'll be better off.