What happens if someone drinks deionized water?
Deionized water is harmless. Drink all you want. The water will quickly dissolve some sugars and electrolytes from your mouth and especially from your digestive system, and will become just plain water. The only potential harm from deionized water might come from the resin used to demineralize the water–not only are these resin beds somewhat limited in their capacity, but they are also hospitable breeding grounds for bacteria. In general, however, the bacteria which grows in clean water is usually harmless. The problem with deionized water is the cost–it is just not worth the price from a drinking water perspective when so many other, less expensive, water purification systems exist. By the same token, mineral water, with a total dissolved solids of more than 1000 parts per million, is also no better or worse for you. From a nutritional standpoint, there are almost no nutrients or minerals in any potable water, certainly not enough to be nutritionally significant, including expensive
