Are the beneficial minerals filtered out by the British Berkefeld® systems?
No, and that's just as well :)
The property of British Berkefled® filters is that they retain undesirable pollutants but allow minerals to pass through in ionic form, which are beneficial to health. These minerals include calcium, potassium and magnesium. Heavy metals such as aluminium, chromium, copper and cadmium are neutralised.
The analysis results for British Berkefeld® filters can be consulted on this page.