Comparison of the mineral content of tap water and bottled waters
OBJECTIVES: Because of growing concern that constituents of drinking water may have adverse health effects, consumption of tap water in North America has decreased and consumption of bottled water has increased. Our objectives were to 1) determine whether North American tap water contains clinically important levels of calcium (Ca2+), magnesium (Mg2+), and sodium (Na+) and 2) determine whether differences in mineral content of tap water and commercially available bottled waters are clinically important.
DESIGN: We obtained mineral analysis reports from municipal water authorities of 21 major North American cities. Mineral content of tap water was compared with published data regarding commercially available bottled waters and with dietary reference intakes (DRIs).
MEASUREMENTS AND MAIN RESULTS: Mineral levels varied among tap water sources in North America and among bottled waters. European bottled waters generally contained higher mineral levels than North American tap water sources and North American bottled waters. For half of the tap water sources we examined, adults may fulfill between 8% and 16% of their Ca2+ DRI and between 6% and 31% of their Mg2+ DRI by drinking 2 liters per day. One liter of most moderate mineralization European bottled waters contained between 20% and 58% of the Ca2+ DRI and between 16% and 41% of the Mg2+ DRI in adults. High mineralization bottled waters often contained up to half of the maximum recommended daily intake of Na+.
CONCLUSION: Drinking water sources available to North Americans may contain high levels of Ca2+, Mg2+, and Na+ and may provide clinically important portions of the recommended dietary intake of these minerals. Physicians should encourage patients to check the mineral content of their drinking water, whether tap or bottled, and choose water most appropriate for their needs.
Key wordstap water bottled water calcium magnesium sodium
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- 2.Shy CM, Stroba RJ. Air and water pollution. In: Schottenfeld D, Fraumeni JF, eds. Cancer epidemiology and prevention. Philadelphia, Pa: W.B. Saunders; 1982:336–63.Google Scholar
- 8.Crawford MD, Gardner MJ. Mortality and hardness of local water supplies. Lancet. 1968; 1:860–2.Google Scholar
- 9.Schroeder HA. Municipal drinking water and cardiovascular death rates. JAMA. 1966; 95:125–9.Google Scholar
- 13.Eisenberg MJ. Magnesium deficiency and cardiac arrhythmias. NY State J Med. 1986; 86:133–6.Google Scholar
- 20.Heany RP, Gallagher JC, Johnston CC, et al. Calcium nutrition and bone health in the elderly. Am J Clin Nutr. 1982; 36:986–1013.Google Scholar
- 21.The Surgeon General’s Report on Nutrition and Health. Summary and recommendations. Washington, DC: DHHS (PHS), Publication No. 88-50211; 1988.Google Scholar
- 22.McDowell LR. Minerals in Animal and Human Nutrition. San Diego, Ca: Academic Press; 1992:26–73, 78–95, 98–137.Google Scholar
- 23.Whitney EN, Corinne BC, Sharon RR. Understanding normal and clinical nutrition. 3rd ed. St. Paul, Minn: West Publishing Company; 1991:271–313, 853–92.Google Scholar
- 24.Marx A, Neutra RR. Magnesium in drinking water and ischemic heart disease. Epidemiol Rev. 1999; 19:258–72.Google Scholar
- 26.Löwik MR, Grrot EH, Binnerts WT. Magnesium and public health: the impact of drinking water. In: Trace substances in environmental health, XVI: Proceedings of the University of Missouri’s 16th Annual Conference on Trace Substances in Environmental health. Columbia, Mo: University of Missouri-Columbia; 1982:189–95.Google Scholar
- 27.Alfonso JF, De Alvarez RR. Effects of mercury on human gestation. Am J Obstet Gynecol. 1984; 75:18–24.Google Scholar
- 28.Durlach J. Recommended dietary amounts of magnesium: Mg RDA. Magnesium Res. 1989; 2:195–203.Google Scholar
- 29.Allen HAJ. An investigation of water hardness, calcium, and magnesium in relation to mortality in Ontario. PhD Thesis. University of Waterloo, Ontario, Canada; 1972.Google Scholar
- 33.Kinney JM, Jeejeebhoy DJ, Hill GL, Owen OE. Nutrition and metabolism in patient care. 1st ed. Philadelphia, Pa: WB Saunders; 1988:61–88, 445–464, 701–726.Google Scholar
- 34.Beverage Marketing Corporation. Bottled Water in the U.S. 1995 ed.Google Scholar
- 35.Prince GW. Smoke on the water. Beverage World. 1996; (March):50–4.Google Scholar
- 36.Population Estimates Program, Population Division, U.S. Bureau of the Census, Washington, DC.Google Scholar
- 37.Draft Ground Water Disinfection Rule, Office of Drinking Water, U.S. Environmental Protection Agency, Washington, DC, 1992.Google Scholar
- 38.von Wiesenberger A. The Pocket Guide to Bottled Water. 1st ed. Chicago, Ill: Contemporary Books; 1991.Google Scholar
- 39.Green T, Green M. The Good Water Guide. London, England: Rosendale Press; 1994.Google Scholar
- 40.Hammer MJ. Water and Wastewater Technology. 3rd ed. Englewood Cliffs, NJ: Prentice Hall; 1996:21.Google Scholar
- 41.Committee on Dietary Reference Intakes. Dietary Reference Intakes for Calcium, Phosphorous, Magnesium, Vitamin D, and Fluoride. Washington, DC: National Academy Press; 1997.Google Scholar
- 42.De Planter A. Bowes & Church’s food values of portions commonly used. Pennington JAT, ed. Philadelphi, Pa: Lippincott; 1994.Google Scholar
- 43.Recommended Dietary Allowances. 10th ed. Washington, DC: National Academy Press; 1989:253.Google Scholar
- 44.Cavallo G. Water, water everywhere...but how much is safe to drink? Cardiac Alert. 1987; 9:4–6.Google Scholar
- 45.Shils ME, Olson JA, Shike M, Ross AC, eds. Modern Nutrition in Health and Disease. Baltimore, Md: Williams & Wilkins; 1999.Google Scholar