For many years it was purported by MD's and the media that the only nutrients needed to build bone mass were calcium and vitamin D. Yet, as understandings surrounding the functions of nutrients such as Magnesium, Vitamin K2, and Boron in bone formation developed, it became clear that what your body does with calcium can be just as important as how much you get. Bone is a very complex, dynamic tissue; and, as I have said many times, adding more calcium to make more bone is like adding more eggs to make more cake. You need the whole recipe, not just one (or two) ingredients.
Though adequate calcium is definitely essential, there is an entire spectrum of nutrients directly or indirectly involved in laying down new bone mass. At least sixteen minerals and vitamins are documented as playing a role, as well as protein like collagen, which forms the core of your bone matrix, and I suspect many more trace minerals will be implicated as our understanding of this process advances.
Firstly, as we at Optimum Health have always informed people, it is extremely important to ensure you are getting enough magnesium to balance your calcium. Calcium and magnesium serve opposing roles to balance-out many bodily functions, including those of your bones, muscles and nerves. 
In addition to magnesium, Vitamin K2 plays a critically important role by activating, (i.e. carboxylating), a protein called osteocalcin, which allows the collagen matrix of your bones to incorporate and hold on to minerals. [2-5] Said plainly, Vitamin K2 helps keep your calcium in your hard tissues where you want it, (i.e. bones), and out of your soft tissues where you don't (i.e. your arteries).
Additionally, the mineral boron, through a series of interactions in hormone and mineral metabolism, reduces the urinary excretion of the main bone-building nutrients calcium, magnesium, and phosphorous, as well as maintaining blood levels of vitamin D. [6-10]
Yet, despite the myriad of bone-building combinations on the market that contain these nutrients, since I started counseling people on nutrition and supplementation in 1986 few to none of these products seemed to improve people’s bone density scores with any consistency. This was until we started recommending formulations containing Coral Calcium with added magnesium and vitamin D. This formula has now been updated to also include Vitamin K2, and Boron.
Coral Calcium is more than just calcium. It is actually a broad spectrum mineral complex very rich in hard to find trace minerals, many of which play roles in health that are still being discovered. In many instances the improvements in bone density scores we have witnessed over 6 to 18 month periods in clients have been quite dramatic.
Many people take 4 capsules daily, yielding 1000mg of elemental Calcium, 700mg of elemental magnesium, (i.e. a 3:2 ratio), and 600 I.U of vitamin D.
Each capsule is now enhanced with 700mcg of boron, 30mcg of vitamin K, and most people add extra vitamin D.
Related: Coral Calcium Complete
The most plausible explanation for the observed effectiveness of Coral Calcium is that the trace minerals, which form the majority of the coral complex, have a positive effect on how minerals are utilized by the body, and incorporated into bone. Or perhaps it is the very alkaline pH of the coral complex in solution that helps the body reverse bone loss….or more likely both factors play a role.
Regardless, these have been our observations over the last twenty years: No matter how impressive a bone-building formula may sound, or how much evidence there may be for its ingredients, our experience is that Coral Calcium seems to produce better results, based on reported bone density scans. And as we have always said “it’s the result that counts”. i.e. What actually happens is much more important than the theory which supports or refutes it, especially since the latter tends to change every decade or so.