Coral Calcium: Hype or Highly Effective Supplement?


Photos courtesy of the National Oceanic and Atmospheric Administration

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Could a coral calcium supplement really help keep us healthy and vital as we age? Is it better than other forms of calcium, worthy of its higher cost?

Questions surround coral calcium. But for Fred Runnels, the answer to all these questions is a definite yes. Based on his personal experience and professional knowledge of chemistry, Runnels is a confirmed devotee of nutritional supplements. A personal-care formulating chemist in Seattle for the last 60 years, Runnels is still going strong — running his own business every day at age 84. That, he says, is thanks to calcium, which ended his 40-year battle with excruciating pain.

Runnels took a bad fall at age 4, and an athletic injury at age 17 caused his back to hurt intensely for the first time — a pattern that continued until he was 54. His chronically misaligned back was so painful that, when driving, Runnels would take every exit from the freeway to stop and stretch his spine over the hood of the car. “It brought tears to my eyes,” he says.

By age 50, Runnels was advised to undergo a surgical spinal fusion. He declined — a decision that caused Runnels’ doctor to “fire” him as a patient. Four years later, Runnels suffered a burn at work. While on bed rest, he took large doses of several nutrients to heal the burn. Lo and behold, his back pain let up for the first time. He narrowed down the source to the calcium he’d been taking. And calcium has kept him pain-free (as long as he takes it daily) for 30 years.

Eighteen months ago, Runnels switched to coral calcium, which he says yielded the best results yet. Coral calcium has become a nutrition phenomenon over the past few years, and the subject of its fair share of controversy. Proponents argue it is a superior form of calcium. Critics claim it is an overpriced source of poorly absorbable calcium.

What Is Coral Calcium?

Ayurvedic practitioners have used coral as a source of supplemental calcium for centuries. A form of calcium carbonate, it differs from other forms in that it contains minute amounts of 73 trace minerals (see “Which Calcium is Right for You?” on Page 40).

There’s no doubt these trace minerals are beneficial. Research has shown that calcium works better, especially for bone building, when accompanied by other minerals. But are the quantities high enough to actually make any difference? Runnels thinks the extra minerals are the reason coral calcium is so effective.

Coral calcium contains a ratio of 2 parts calcium to 1 part magnesium (about 20 percent calcium and 10 percent magnesium) — the same ratio our bones contain. That ratio has been the standard recommendation of holistic health practitioners for many years.

Coral calcium is mined from aboveground aged coral rock deposits or is scooped up as “marine” coral sand from around reefs, and therefore is very pure. Sometimes called “fossilized” coral, it’s not taken from living reefs in the sea.

Coral calcium typically has been mined in Okinawa, Japan, but Brazilian types are now becoming available. This material, from a different variety of coral, is harvested on sandy beaches and contains 12 times the trace mineral content of Okinawan coral. Although extensive research is said to have been done on this material, the research is mainly in Portuguese and little of it has made its way out of Brazil.

Some fossilized coral is washed up on beaches, but its low magnesium content makes it inferior. Check product labels to be sure your supplement contains magnesium. Likewise, bleached coral may have a reduced mineral profile. Detractors claim that coral calcium is high in aluminum and lead, although the total amount one would ever consume in a supplement is miniscule.

The Start of the Controversy

Coral calcium’s reputation was seriously wounded in 2003 when an infomercial marketer, who also was coral calcium’s main popularizer, exaggerated the benefits to sell the product and got into trouble with the Federal Trade Commission and the Food and Drug Administration. The problem involved false or unsubstantiated claims for coral calcium, not issues with the calcium itself. The company agreed to stop making claims that their coral calcium product could treat or cure cancer, multiple sclerosis, heart disease, high blood pressure or other serious diseases. That does not mean that coral calcium is not good — just that it might not be the miracle cure.

Coral calcium is not a panacea, but it’s a good source of calcium and trace minerals.

The Claims and the Research

• Coral calcium aficionados claim the mineral provides the body with 95 to 100 percent absorption. Based on current knowledge of the research, many health professionals find this claim doubtful — coral calcium is a form of calcium carbonate, and studies of calcium carbonate have not found absorption to be that high. Most practitioners believe there is nothing so different about coral calcium that would cause absorption to improve that much. This does not mean coral calcium is bad — just that health claims for it have been exaggerated.

• Coral calcium mainly has been promoted as a way to make the body more alkaline. Americans tend to be overly “acid” in pH, due to high levels of stress and excessive consumption of refined carbohydrates and protein. It’s true that coral calcium can help alkalinize the body, but that’s true of all forms of calcium, not just coral.

• Proponents claim that, because coral calcium was formed in living tissue, it has a different structure and is more absorbable than other forms of calcium. In general, it’s true that organic forms of minerals are better absorbed, as is the case with amino acid chelates.

• One small study of 12 subjects, published in the Journal of Nutritional Science and Vitaminology in 1999, compared coral and carbonate forms of calcium given in food. The coral was better absorbed. However, naturopathic doctor Michael Murray criticizes this study as being fraught with errors involving inaccurate measurements of absorption.

• A Japanese rat study, also conducted in 1999, found better absorption from coral calcium. The scientists did not confirm the reason, but it may have been from the magnesium content.

Bottom line? Coral calcium is not a panacea, but it is a good source of calcium, magnesium and trace minerals.

Karta Purkh Singh Khalsa, a frequent contributor to Herbs for Health, is an adjunct faculty member in the botanical medicine department of Bastyr University in Kenmore, Washington. Khalsa’s book Body Balance is available on our Bookshelf, Page 58.

The reference list for this article is extensive. If you would like a copy, please send a self-addressed, stamped envelope to “Coral Calcium,” Herbs for Health, 1503 SW 42nd St., Topeka, KS 66609; or e-mail us at