We often get asked, "Shouldn’t I drink water that contains trace minerals?" We do need minerals as part of our nutrition, but water is not a reliable source for minerals. Often the trace minerals are not even present in the water. This becomes apparent when we consider how minerals get in the water.
The concentration and type of minerals is entirely dependent on where water lands on the earth. Rain or snow that lands on fairly flat, porous ground will seep into the soil, slowly traveling through small crevices in rock and making its way to an underground aquifer. This is known as ground water because of its extensive contact with the ground. Rain or snow falling in the mountains will collect quickly in creeks, streams, rivers, ponds and lakes. This is considered surface water because it remains on the surface rather than traveling through the ground to an aquifer.
When the rain or snow falls from sky, it contains no minerals. The minerals come from its contact with the soil. The local geology will determine what minerals leach into the water. In areas like the mid-west with lots of limestone, the water will contain calcium and magnesium. But in areas like the northwest with lots of granite and basalt, the water will contain iron and manganese. Because the geology varies across the planet, the minerals found in the water, and its concentration will vary as well. Ground water may have high concentrations of some important minerals but be entirely devoid of other important minerals. Surface water, due to its limited contact with the ground, will have a much lower concentration of minerals. Not all minerals are considered healthful but may be found in the water as well. Lead and arsenic are examples of minerals that may be found in water yet are not heathful.
Because all water supplies will vary in the type and concentration of minerals present, it becomes clear that water is not a reliable source for minerals as part of a healthful dietary regimen. Our review of books and websites on the topic of "Nutrition", consistently site food as the primary source for minerals. Plants are able to absorb the minerals from the ground. People and animals eat the plants and absorb the minerals from the plants. Meat eaters also get minerals from eating other animals.
We are not designed to rely on minerals from water – plants are. Our bodies may use minerals from the water but water, as the source of minerals, will never provide all that is needed in the correct concentrations. In many cities like Seattle, Portland, New York and Boston, where the water supply comes from snow water run off, the mineral content is so low that its contribution to the recommended daily intake is inconsequential.
Dietitians and nutritionists recommend getting minerals from a variety of food sources so that you get an adequate quantity, along with vitamins, fiber and other basic nutrients. Regardless of what type of water one drinks, mineral supplements are a good option for people who may not be getting enough minerals from their diet. Check with your physician to determine what type of mineral supplementation is right for you.
References
- LJ Dunne, Kirschmann, Nutrition Almanac, 3rd Edition, McGraw Hill 1990
- W. Marktl. “Health Related Effects of Natural Mineral Waters”. Wien Klin Wochenschr. 2009; 1121(17-18): 544-50 article in German. Abstract in English: http://www.ncbi.nlm.noh.gov/pubmed/19890742 (accessed 9/11/10)
- http://www.thefoodchart.com/dietary-minerals.php (accessed 9/12/10)
- http://www.ivy-rose.co.uk/HumanBody-Science/Minerals.php (accessed 9/10/10)