Water that contains natural minerals and alkaline pH is associated with lower mortality from heart disease and cancer, and overall good health. The drinking water in the 100 largest cities in the US were found to have 10% to 25% reduction in the amount of cancer deaths when the drinking water had a moderately high level of minerals and had an alkaline pH (above 7.0).
The National Research Council (National Academy of Sciences) states that minerals in water generally contributes a small amount toward total calcium and magnesium human dietary needs.
According to the World Health Organization (WHO), "calcium and magnesium are important parts of drinking water and are of both direct and indirect health significance. A certain minimum amount of these elements in drinking water is desirable since their deficiency poses at least comparable health risk of exceeding the limit for some toxic substances does.", and "There is a need to balance the potential beneficial aspects of those filter devices that concurrently remove trace contaminants against the potential negative effects of reducing the calcium and/or magnesium levels to below the recommended levels in drinking-waters."