Should you drink Reverse Osmosis water?
The principle of drinking ‘Pure’ water as suggested by the RO proponents is that plain H2O is the purest form of water, and often they cite the evaporated rainwater as an example.
While this may sound logical, a cursory glance at this diagram of the Water Cycle very quickly dispels that theory, simply because our normal and natural method of getting water from rain goes through one very important process before we get to drink it; it runs down the mountainside and comes into contact with rocks, soil and plants and absorbs essential nutrients.
Does this principle hold true for RO water?
This same question was researched in 2004, commissioned by WHO (World Health Organisation) and quotations from those findings tell a very different story.

Patients diagnosed with colon cancer who had abundant vitamin D in their blood were less likely to die during a follow-up period than those who were deficient in the vitamin, according to a new study by scientists at Dana-Farber Cancer Institute.
Usually we don’t associate coffee with healthy foods. On the contrary, it has a long history of being blamed for many evils, from stunted growth to claims that it causes heart disease and cancer. Recent research, though, indicates that coffee is not the bad boy some make it out to be; in fact, it may be just the opposite. These studies suggest that it doesn’t just give us a boost in the morning; it is a highly beneficial and healthy drink.