What else should I take besides calcium for my bones (Part V of "Should I take calcium")

Calcium is necessary to build and maintain strong bones, but it is not necessarily sufficient.  To focus in on calcium supplements as a top priority solution to the prevention and treatment of osteoporosis is to lose sight of the complexity of bone-building and maintenance, and to risk the unwanted consequences of too much of a single good thing.

Vitamin K, as mentioned in Part IV of this series, is essential to the modification of proteins integral to blood-clotting and the proper use of calcium.  Vitamin K1, available from plants particularly of the leafy green variety such as kale, is the K form involved with normal blood coagulation.  People are rarely deficient in K1 insofar as clotting is concerned. At times, individuals who have experienced problems such as deep vein thrombosis (clot) in leg veins or pulmonary emboli (blood clots traveling to the lungs) are put on warfarin (aka Coumadin) which partially blocks the function of K1 thus preventing future unwanted clot formation.  Unfortunately, people on long-term warfarin are known to be at greater risk for arterial calcification.

K1 can be converted to K2 by intestinal bacteria.  While there is dispute as to whether or not bacterial K2 is available for absorption into the body through the gut wall, it is known that women with high intake of K1 are less likely to sustain hip fractures, and lettuce intake--a good source of K1--was inversely proportional to future incidence of hip fractures in the Nurses Health Study(1).  Those medical professionals eating lettuce once or more daily had a nearly 50% hip fracture risk reduction compared to those downing one or less salads per week. 

It is difficult to take in enough K1, however, to meet your K2 requirements.  Researchers from The Netherlands compared the efficacy of K1 to K2 in the MK-7 form with respect to the production of proteins essential to proper bone calcification and found the K2 more effective and far more long-acting in its bone-forming functions(2).

Therefore, in order to build strong bones AND keep unwanted calcium out of your blood vessels, daily intake of K2--especially the MK-7 molecule--is absolutely the answer.  Besides the Rotterdam study cited in my previous post, multiple other clinical studies correlate K2 intake with long term vascular health. 

While calcium is good and necessary, vitamin K2 is essential.  Vitamin D, of course, is also crucial as are multiple other micro-nutrients.  In the sixth and final installment of this series, I'll give you my best advice as to "Should you take calcium" and what you should be taking as well for optimal bone and vascular health.
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1) Feskanich D et al.  Vitamin K and Hip Fractures in Women, a Prospective Study.  Am J Clin Nutr January 1999 vol. 69 no. 1 74-79. 
2) Schurgers LJ et al. Vitamin K–Containing Dietary Supplements: Comparison of Synthetic Vitamin K1 and Natto-derived Menaquinone-7. Blood April 15, 2007 vol. 109 no. 8 3279-3283.