Coral calcium is usually obtained from coral sand. These deposits of sand are part of coral reef, usually collected directly from coastal land or the shallow waters surrounding it.
To manufacture coral calcium, coral is first refined to remove any pollutants or other unwanted substances, then it is ground into a powder and this powder is then sold in capsules or other forms.
Coral calcium supplements contain most of the calcium carbonate, but also contain small amounts of magnesium and other trace minerals.
Coral calcium has a similar structure to human bone and has been used as a bone graft material for over 30 years.
Nowadays, it is used to prevent or treat low calcium levels in people who do not get enough of this nutrient through diet alone.
Read more - (Calcium Deficiency: symptoms, causes, treatment )