Calcium in drinking water does not have any negative effects in the human body, and the National Research Council reports that it contributes to daily dietary requirements, according to the Water Research Center. Some of the council’s research provides inconclusive evidence that hard water, or water with a high amount of calcium and other dissolved solids, may reduce the risk of cardiovascular disease mortality, as of 2015.
Calcium builds strong bones and teeth, which contain over 99 percent of the body’s calcium, explains WebMD. The body is constantly breaking down old bone tissue and growing new tissue, and calcium intake is essential for this process. The cardiovascular and nervous systems also require calcium in order to function properly. Blood and bodily tissues contain calcium as well, and bones can store extra calcium and distribute it when the body requires it.
The other most common contributor to hard water is magnesium, which is also harmless in water and contributes to an individual’s dietary needs. These minerals appear naturally in water, as the water absorbs them and other minerals as it passes through the ground, explains the Water Research Center. Individuals can test the hardness of their water by consulting a professional water tester or by using a home kit. Municipal suppliers also provide this information upon request.