Composition

• Coral calcium is made up mostly of calcium carbonate. However, it also contains small amounts of various trace minerals, such as magnesium.
  
  

Harvesting

• Coral calcium cannot be harvested from living coral reefs because they are so fragile. Because of this, coral calcium is gathered from limestone rocks that are left over from old coral reefs and have absorbed this calcium into them.
  
  

Benefits

• There are a number of claims made that coral calcium is healthier than regular calcium supplements. These claims note that coral calcium is not only a good source of calcium, but also of other trace minerals that may not be easily obtained.
  
  

Health Risks

• Those who don't see coral calcium as beneficial actually point out possible health risks. This is because coral in some parts of the world, particularly off the coast of Japan, has absorbed high amounts of mercury, which could possibly be in coral calcium harvested there.
  
  

Environmental Risks

• Environmentalists have been talking about how fragile the disappearing coral reefs of the world are for some time now. Coral calcium harvesting has taken a lot of fire because it is believed to senselessly endanger coral reefs.