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Coral Calcium


Updated November 29, 2012

What is Coral Calcium?

Coral calcium is heavily promoted as a superior form of calcium. It is a form of calcium derived from coral reefs.

Corals themselves are tiny animals related to jellyfish and sea anemones. Coral forms a hard protective skeleton of calcium carbonate. When coral dies, new generations of coral grow on top of the calcium carbonate remains, eventually forming a coral reef.

Much of the hype stems from the fact that coral calcium is harvested from coral in Okinawa, Japan. Okinawans, are thought to have the longest life expectancy in the world and have low rates of heart disease and cancer.

Marketers of coral calcium say it is because Okinawans drink water containing coral calcium. But researchers involved with the Okinawa Centenarian Study debunk this claim, saying that although hard water (water high in minerals such as calcium and magnesium) does increase calcium intake, Okinawans still consume less calcium than people in Western countries.

Benefits of Coral Calcium

Despite claims made by marketers, there is no evidence that coral calcium is superior to any other form of calcium. Coral calcium is calcium carbonate, the most common type of calcium on the market. Coral calcium isn't chemically different from other calcium carbonate products.

Although coral calcium contains small amounts of trace elements, such as manganese, there is no evidence that the trace minerals are any better than those you would find in a high quality multivitamin and mineral supplement.


Coral calcium is generaly more expensive than other sources of calcium carbonate.

Potential Side Effects and Safety Concerns

People with shellfish allergies may develop allergic reactions after ingesting coral calcium supplements.

Also, not all of the trace elements found in coral calcium, such as cadmium, uranium, and mercury, are considered desirable.

There are concerns that coral calcium, like other natural calcium carbonate sources oyster shell, dolomite, and bone meal, may contain lead.


"Consumer Advisory: Coral Calcium" NCCAM, National Institutes of Health. November 2004. 8 Sept 2006. <http://nccam.nih.gov/health/alerts/coral/coral.htm>

"Marketers of Coral Calcium Product Are Prohibited from Making Disease Treatment and Cure Claims in Advertising" Federal Trade Commission. 22 Jan 2004. 8 Sept 2006. <http://www.ftc.gov/opa/2004/01/barefoot.htm>

"Okinawa Centenarian Study Position Statement on Coral Calcium" Okinawa Centenarian Study. 7 Jan 2003. 8 Sept 2006. <http://okinawaprogram.com/coral_calcium/coral-calcium.html>

"Coral calcium: Safe for people with shellfish allergies?" Mayo Clinic Website. 24 Feb 2005. 8 Sept 2006. <http://www.mayoclinic.com/health/calcium/AN00494>

"Coral Calcium" Claims Debunked. ConsumerAffairs.com. 10 Feb 2003. 8 Sept 2006. <http://www.consumeraffairs.com/news03/coral.html>

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