Barefoot Coral Calcium Complete™ Value Pack - Get 3 bottles for only $24.50 Among the oldest and most primitive of organisms containg calcium is coral. Coral reefs surround islands everywhere in the world, but the coral reefs surrounding Okinawa have proved to be like no other. Calcium is involved in almost every biological function. It plays a critical role in nerve transmission, heart function, blood pressure regulation, blood clotting processes, and bone building. Calcium is 35% of our body's mineral makeup and our number one mineral and is responsible for feeding every cell. .