Yes you can add some nutmeg to your coffee.
I add nutmeg to my coffee and it makes it taste really good.
I also sometimes like to add a bit of cinnamon to the coffee as well along with the nutmeg for an even better taste.
Nutmeg coffee or Cinnamon and Nutmeg Coffee is great and adding the Nutmeg and/or Cinnamon to the coffee is healthy as well and gives it a nice aroma.
It just takes a pinch of Nutmeg or Cinnamon in the coffee to give it a great flavor.