Coral calcium is a dietary supplement derived from fossilized coral reefs. It may be marketed as a cure for various conditions or diseases, though there are no definitive scientific studies to support such claims. Like other sources of calcium, it is composed of calcium carbonate, however, it typically contains trace minerals that differentiate it from other calcium sources. These trace minerals may be the origin of claims that coral calcium has curative properties, and they could possibly also provide other beneficial effects.
Calcium is an essential element to human life, which, in many cases, can be obtained by eating a normal, healthy diet. The calcium carbonate present in coral calcium can act as a supplement to a diet lacking in calcium, or it may be taken by people who require more than their diet would otherwise provide. Though coral calcium is largely the same as calcium obtained from other sources, the various trace minerals it contains may render it more beneficial. The precise benefits provided may not be scientifically proven, though ultimately it is up to the individual to decide which source of calcium works best for his or her needs.
Although coral reefs may seem like the natural source for such a supplement, coral calcium is most often obtained by processing limestone. Reefs are protected from exploitation or harm all around the world, and it is very difficult to harvest dead coral without damaging the living reef. Additionally, limestone deposits on land all began underwater — as coral and other marine organisms — so once they have been processed and purified, they provide more or less the same product that would otherwise be obtained from a living reef. Once harvested, the coral or limestone is ground up, heated to a very high temperature, and sometimes treated with ozone to remove certain impurities.
Users should know that the location where the coral or limestone was sourced can present potential health concerns, especially if the coral was obtained from shallow reefs instead of from limestone. Though coral grows very slowly, it is still possible for it to pick up pollutants from its environment. Such impurities may be present in limestone as well, though certain sources of coral may also be contaminated with lead and other heavy metals. Since many countries around the world do not have strict regulations on dietary supplements, it may be difficult to determine whether or not a particular batch of coral calcium could have come from a contaminated area.