Reverse Osmosis (RO) is one of the most effective filtration methods available; it removes over 99% of all dissolved solids from water. In a quest for safe water, many people turn to reverse osmosis systems in the mistaken belief that since the water is clean, it is healthy to drink. Astonishingly, nothing could be further from the truth, people who drink reverse osmosis water may become mineral deficient, which, according to the World Health Organization (WHO) could detrimental to your health.
Water – The Universal Solvent
Water is known in chemistry as “The Universal Solvent” because it has the power to dissolve almost anything. In nature, water dissolves the minerals found in the rocks it flows past; those minerals then become part of the water. Water that comes out of the tap will contain many minerals such as calcium, magnesium and sodium. Numerous studies have shown that you can get useful amounts of important minerals like calcium from water. Studies comparing people who have hard water (which contains large amounts of dissolved minerals) with people who have soft water (few minerals) reveal that the people who drink hard water have less health problems than people who drink soft water. 
Reverse Osmosis Water is Hungry for Minerals
So what happens when you drink reverse osmosis water? Water produced by reverse osmosis is soft water, it contains almost no minerals – and that’s a problem. If you drink mineral-deficient reverse osmosis water, it may dissolve minerals from your bones and tissues. 
How to Make Reverse Osmosis Water Safe to Drink
If you already have an reverse osmosis system, or plan on getting one, you will need to re-mineralize the water in order to put in the minerals that reverse osmosis takes out. The best way to remineralize reverse osmosis water is with a remineralizing cartridge; it attaches to the output from your reverse osmosis system and restores essential minerals to your water.
For example, the Life Coral Calcium Remineralizer restores calcium – in coral form – to your water along with 74 other minerals. With this remineralizing cartridge, your reverse osmosis water will contain minerals like calcium and magnesium . Water remineralized this way also tastes better than straight RO water does. If you want minerals in the water from your reverse osmosis system, you need a remineralizing cartridge!
Ong, Choon. “Minerals from drinking-water: Bioavailability for various world populations and health implications.” WHO | Water Sanitation Health. World Health Organization, 17 Aug 2004. Web. 9 Jul 2013. <http://www.who.int/water_sanitation_health/dwq/nutbioavailability/en/>.
Kozisek, F. “Nutrients in Drinking Water.” WHO | Water Sanitation Health. World Health Organization. Web. 9 Jul 2013. <http://www.who.int/water_sanitation_health/dwq/nutrientsindw.pdf>.