Coral calcium is a natural supplement said to be helpful in treating everything from diabetes to arthritis, osteoporosis and cancer. While calcium is a critical mineral for the development of healthy bones and teeth, coral calcium does not demonstrate proven health benefits and has been shown to cause several side effects. Coral calcium side effects include gastrointestinal problems and potential contamination from poisonous elements in the environment from which it is gathered. In addition, the harvesting of coral calcium impacts the ecology of the ocean.

Typical coral calcium side effects include gastrointestinal ailments such as constipation, excess flatulence and intestinal bloating. Nausea and dry mouth have also been reported in some cases. In instances where people may be prone to developing calcified stones, kidney stones may form.

Increasing fluid intake and taking the supplements with food will decrease some of the gastrointestinal side effects associated with coral calcium. Users are urged to take coral calcium only within recommended dosages. Consumers should consult a physician before taking the supplement.

While coral calcium is said to carry 70 minerals important to the human body, it is susceptible to contamination by trace elements that may be found in its environment. Coral is extremely porous and, therefore, prone to absorbing the elements around it. Research has shown that many corals contain strontium, manganese and uranium, all of which are harmful to human health. Depending on the area in which the coral calcium is harvested, poisonous elements and even toxic materials may be present and absorbed by the coral.

Coral calcium from Okinawa, Japan, one of the most popular harvesting sites, contains 25 percent calcium. Up to 70 additional compounds have been found in Okinawa coral calcium. If users take additional dietary supplements with the same compounds, there is some risk of overdosing on these compounds.

Coral calcium side effects also can be felt by the environment. Corals take millions of years to form and provide nutrients important to healthy ocean ecology. Although coral calcium is supposed to be taken from above-ground coral deposits and there are laws protecting live coral reefs, there is no guarantee that the laws are strictly enforced throughout the world. The destruction of live coral reefs threatens the well-being of the entire ocean ecosystem. Another of the coral calcium side effects to consider is a financial one, because a month’s supply of the supplement costs about three times the amount of other forms of calcium supplements.