Coral calcium is a salt derived from fossilised coastal coral beds. It consists mostly of calcium carbonate, with some magnesium and other trace elements. The use of coral for medicinal purposes dates back some 5000 years, and indeed today, many biocompounds used in medicines were first isolated from species with a coral ecosystem.
Harvesting live coral today is of course often illegal and always ethically questionable. The harvesting process for fossilised coral calcium was first developed in Japan in the 1950s.
Coral calcium is an antioxidant, and can thereby help to protect against the cell damage caused by free radicals. It is also thought to help protect against the premature ageing of brain cells, although no human studies have been done on this subject. Coral calcium has also been shown to accelerate bone growth.
Anecdotally, coral calcium has been linked with longevity – probably because the population of Okinawa in Japan, where the coral calcium processing method was developed, have a reputation for being very long lived, a fact which has in part been attributed to the minerals present in the fish harvested from their coral reef.