Coral supplements are made of ground limestone, which is a form of calcium carbonate. While it is common knowledge that calcium is necessary for strong bones, there is no evidence to back the claims made by coral calcium manufacturers that calcium sourced from coral can cure disease or increase your body's calcium intake any better than a regular calcium carbonate supplement. In fact, many companies have been ordered by the Federal Trade Commission to stop marketing their products as a drug -- when the pills were tested, many didn't contain the amount of calcium they were supposed to, and many contained high levels of lead. If you decide to try a coral calcium supplement, choose a reputable brand.
Brazil Live Coral Calcium
According to CoralCalcium-Watchdog.com, a nonprofit group that cuts through marketing hype and publishes facts about coral calcium supplements, Brazil Live Coral Calcium earns top marks for both quality and value. At $0.26/g as of 2010, it is one of the lowest-cost coral supplements available, and it is live-harvested from Brazilian coral reefs. This makes it lower in contaminants and impurities, but it is also ecologically unsound to physically alter a living coral reef.
HTN's Alka-Line Coral Calcium
In a comparison test conducted by the Wolfe Clinic, HTN's Alka-Line Coral Calcium supplements came out on top both in the capsule and powdered form. This brand produced the highest blood pH, the lowest electrical conductivity reading and the lowest oxygen-reduction results among a field composed of other coral calcium brands and regular calcium carbonate supplements. The results of the comparison indicate that the powdered form is most easily used by the body, but the same brand capsules placed a close second. At about $1/g as of 2010, it is also the most expensive brand to make the list.
True Blue Coral Calcium
True Blue was the second favorite of CoralCalcium-Watchdog.com. At $0.39/g as of 2010, it is still a good value compared to other coral supplement brands, and it is harvested above sea level. This means it doesn't contain as much sand and other contaminants as coral harvested below sea level, and it doesn't have the ecological implications of harvesting live coral.
Coral Advantage came in second in the Wolfe Clinic comparison. Although it came in far behind the HTN supplements, it still showed impressive pH, electrical conductivity and oxygen-reduction potential when compared to other coral supplements, as well as traditional calcium carbonate supplements. At about $0.08 /g as of 2010, it is the least expensive coral supplement on the list.