Do water filters remove valuable minerals?

Q. In your podcast on mineral water, you said that tap water can be a source of minerals such as calcium and magnesium.  If I use a water filtration pitcher to filter my tap water, am I removing these nutrients?

A. Great question!  To answer it, I got in touch with both PUR and Brita, who manufacture water filtration pitchers. Both assured me that any calcium or magnesium that is in your tap water to start with will not be removed by the filtration process.