Actually, this is not the case with distilled water. The water that is sometimes used for research IS capable of leaching minerals from a persons body(i.e. non-ionic and triple distilled water)however, simple distilled water (such as what you buy in the store) is not a strong leaching agent in and of itself. Even distilled water that has been put through a reverse osmosis purification as well as an ozonation procedure still contains small particles and ions. This can be demonstrated by a certain test in which a glass of distilled water is exposed to low-amp currents of electricity from zinc and copper material anode and cathode, respectively. Even the purest of distilled water (except non-ionic water and triple distilled water) will show particulate matter upon passage of electricity through the water.
**As a side note, the worst water that was subjected to this test was Evian. The electrode was caked in black gunk after the test was concluded. This is funny because if you spell EVIAN backwards you get 'naive'. Okay, so it wasn't funny.
Water is absorbed quickly by the body. A certain percentage is excreted in solid waste a few hours later. The rest is either used in the cooling mechanism of sweating or it is ultimately filtered by the kidneys and re-used if needed. Distilled water should not normally leach minerals from the body unless it has been triple distilled--which is reserved for medical and scientific research purposes.
If a person is low enough in potassium or calcium or magnesium or other ions then the addition of ANY water can result in a type of electrolyte abnormality possibly leading to neurogenic diabetes insipidus (which means in English that the kidney cells are not being supplied with enough electrolytes to be able to perform their filtration job).
I am not aware of non-ionic water being sold anymore, although research facilities can still get it. Nonetheless, even these companies are not very profitable considering that a laboratory can make non-ionic water cheaper than they can buy it.
At any rate, triple distilled water and non-ionic water can leach minerals from the body to the extent that if consumed in large quantities can lead to low calcium and low potassium levels but distilled water will not do this in an otherwise normal individual.