I have been hearing about coral calcium everywhere. The companies selling it say it is the best calcium supplement on the market and that it provides many health benefits. Is this true?
Coral calcium has been heavily promoted to the American public as a superior calcium supplement. In reviewing the materials supplied by a manufacturer, Life Extension cannot corroborate this claim. Coral rock consists of calcium carbonate, an inexpensive form of calcium used in products like Tums® and low cost calcium supplements. A meta-analysis of all pertinent published studies showed that calcium citrate is better absorbed than calcium carbonate by approximately 22% to 27%. Calcium bisglycinate has been shown to be better absorbed than calcium citrate [Calcified Tissue International 1990, 46:300-304]. The manufacturer of coral calcium
bases the superiority claims on a study showing that when compared to other calcium sources, such as milk or cow bone, coral calcium carbonate absorbed better. This is not surprising, since milk and cow bone are hardly ideal ways of supplementing calcium. Calcium should always be taken with vitamin D for optimal assimilation and utilization by the bones. Not all coral calcium supplements appear to provide vitamin D. Coral calcium does supply magnesium, however, there are many calcium supplements that also contain magnesium. The daily recommended intake for calcium is about 1000 elemental milligrams or higher. Some coral calcium supplements only supply 400 mg of elemental calcium in their recommended daily dose. Companies distributing coral calcium sometimes point out that the people of Okinawa, Japan are the longest lived in the world. Since their coral calcium comes from Okinawa, they imply it will make you live longer. Current theories for the longevity enjoyed by Okinawans focuses on their reduced calorie diet, consumption of disease preventing plants, and strong social ties that keeps elderly people part of the family for life. Calcium carbonate has long been considered the cheapest source of calcium. While it is not harmful to take, there are other forms of calcium (citrate and bisglycinate) that have been shown to absorb better. The benefits to
supplementing with calcium are enormous. Coral calcium companies make strong health claims that relate to the benefits of calcium itself, and not necessarily to coral calcium. The only positive comment we can make about the various promoters of coral calcium is that they have raised the public's awareness about the importance of calcium supplementation. A typical person's health will improve if they take coral calcium compared to no calcium at all. To obtain ideal potencies of calcium, take 1000 elemental milligrams of either calcium citrate or calcium bisglycinate every night. Make sure the supplement provides vitamin D3 [Am J Ther 1999 Nov;6(6):313-21].