Some consumers believe that certain natural mineral waters have medicinal properties
or offer other health benefits. Some such waters have higher mineral content,
sometimes significantly higher than concentrations normally accepted in drinkingwater.
They often have a long tradition of use and are often accepted on the basis that
they are considered foods rather than drinking-water per se. Although certain mineral
waters may be useful in providing essential micronutrients, such as calcium and magnesium,
these Guidelines do not make recommendations regarding minimum concentrations
of essential elements because of the uncertainties surrounding mineral
nutrition from drinking-water. Packaged waters with very low mineral content, such
as distilled or demineralized waters, are also consumed. There is insufficient scientific
information on the benefits or hazards of long-term consumption of very low mineral
waters to allow any recommendations to be made (WHO, 2005b; see also the supporting
document Calcium and magnesium in drinking-water; Annex 1).