Your shower head does a lot of work in one year! All those showers everyday you will want to give your shower head some attention.
What you can do is pour some white vinegar in to a sturdy plastic bag make sure you use enough to submerge the showerhead and use a rubber band.
Secure the bag and let the showerhead soak overnight and in the morning remove the bag and run the shower. The process will remove calcium deposits and any bacteria.