Dead pixel of my photos?

Just want to ask. I have an nikon dslr. I'm wondering why if i zoom my picture zoom like almost 200-300percent. I can see some dead pixel… Is there something wrong with my camera body? Lens? Or what?
please help me. And what should i do to fix this problem? Or it is normal?

Are you sure it isn't dirt on the sensor?
Put the camera on manual focus and set focus to infinity
Take a photo of a very light plain subject close to the lens using long exposure and smallest aperture you have - over expose by a couple of stops
You will see in the image if there's dirt as that will be the only thing in focus

Cure is to get the sensor cleaned

There should be a Pixel Mapping function in the menu that will get rid of them, most sensors have a few dead and flipped pixels, some only show up on long exposures.

Most cameras have either dead or hot pixels. You won't get a replacement if you can only see it if you zoom in to 300%.It's probably within the manufacturer's specs. Do you see the faults when you print the image or post it on a web site? If not, don't worry about it. In any event, they're easy enough to fix in post processing.

Pixel peeping, which is what you are doing here, is the surest road to misery and madness. Stop doing it.