Calcium & Magnesium Debate Continues

More than 162 participants from 25 countries attended the symposium on Health Aspects of Calcium and Magnesium in Drinking Water held April 24 to 26, in Baltimore. The symposium was organized by NSF International, the NSF/WHO Collaborating Centre for Drinking Water and the International Life Sciences Institute.

Stan Hazan, senior director of regulatory affairs for NSF, told Water Quality Products the goal of the symposium was to review epidemiological and other health-based information on the potential benefits of magnesium and calcium in drinking water.

This issue, which first attracted attention about four years ago, has remained in the industry spotlight as the outcome could have an impact on all aspects of the water industry, including desalination practices, membrane filtration, central softening in water supplies, and home treatment systems.

The symposium featured more than 30 presentations delivered in 10 sessions. Some of the major topics discussed included: Water as a Source of Dietary Minerals in the World, Controlled Human Exposure Studies of Magnesium and/or Calcium in Diet and Drinking Water, Epidemiological Evidence Linking Drinking Water Components and Health - Cardiovascular and Other Diseases and more. The PowerPoint slides from the presentations will be available at and at

WQA Technical Director Joseph F. Harrison, CWS-VI, P.E., and WQA Technical Services Consultant Regu Regunathan, Ph.D., addressed concerns whether water treatment dealers might face a surge of lawsuits from the public, should the WHO decide to recommend calcium and magnesium in drinking water for health purposes.

According to Harrison, the benefits of consuming softened, treated water far outweigh any potential benefits of consuming hard, untreated water; therefore, WHO should not make such a drinking water recommendation. He also called for scientists to make a distinction between water that is naturally soft, and water softened through a treatment process.

“Any recommended guidance for drinking water hardness will immediately manifest to a broad and influential public health policy. It will affect consumer attitudes toward the safety of their drinking water supplies, and it will significantly direct expenditures of resources toward public health protection. We must insist that the highest levels of evidence be used to guide and set these policies,” Harrison said.

NSF’s Hazan told Water Quality Products that overall, attendees agreed that calcium and magnesium are essential nutrients, and there is evidence to show that daily intakes below threshold levels can be detrimental to human health, with postulation that additional health benefits are possible when intakes exceed threshold levels. Much discussion, however, focused on trying to identify the threshold figure for calcium and magnesium.

“While the final results of the meeting are awaited, one thing is certain. This is an issue that will continue to attract considerable attention and discussion,” Hazan said.

The information presented at the symposium has moved to a WHO expert committee for review. The committee is expected to make recommendations by the end of the year.

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