What you think are calcium facts are really marketing stories not entirely based on science, or at least not the whole picture but just small segments. Unless you have an understanding of the principles involved and correctly apply them, you are doomed to suffer the consequences of CALCIUM jungle fever. Bones are just the tip of the iceberg for calcium actions, and while difficult to believe, calcium is not even among the top few recommendations from science for healthy strong bones. ref ref  Does the cow look out of place in a jungle? Or is this a cow feeding paradise?

Here is a key bone basic from the US Surgeon General's report ref: "The bony skeleton is a remarkable organ that serves both a structural function, providing mobility, support, and protection for the body, and a reservoir function, as the storehouse for essential minerals."

THE HOLLOW BONE SAGA

Vitamin Workshop PRE-ANALYSIS:  This is one possibility. Nutrition researchers had a dilemma to solve. How to prevent fractures due to thinning bones, called osteoporosis. Given the realities of the Standard American Diet, they could either correct the diet to prevent large amounts of calcium being eliminated out of the body, or they could recommend increasing calcium intake to compensate for this loss. Of course, this assumes they knew both of these options were in play, and they had proof that increased calcium intake did indeed prevent fractures. It now is evident that Science let the dairy industry dictate the direction of this answer resulting from very short term increased calcium as dairy increasing bone density. This assumption, in play for many years, even decades, is now in jeopardy and might actually be adverse to long term bone fracture prevention.

Only increasing calcium intake, from foods such as dairy or supplements, can lead to other problems in the body; pH regulation plus artery and soft tissue calcification (ref)associated with brain lesions and heart disease atherosclerosis. Thus it is not just the amount of calcium in the diet, but how it is delivered plus what happens to it once it is inside the body. ref How it is delivered affects the amount of calcium released at one time into the system. Too much can be quickly released from supplements which overwhelms the balance systems to over-respond. article  Nutritionists still to this day exhibit a lack of appreciation for nature's calcium balancing act. As you increase calcium intake, the body reduces the absorption percentage. Why do you think this happens? Absorption percentage is regulated by need. Is it wise to constantly overload the body with calcium?

The body needs just a certain amount of calcium each day to maintain the balance of the blood calcium level. This blood level is the true driver for calcium behavior. Excess or deficiencies of calcium intake cause changes in the body to compensate. This might mean taking calcium out of bone storage when dietary intake is low or preventing absorption, speeding up elimination, as well as packing more into bones when intake is high. If these were the only processes affected by calcium levels, this would be simple to measure and handle, but other hormones and their related activities are involved such as vitamin D activation with side pathways giving protection against infections and cellular DNA damage to cells. There is a domino effect at play that often challenges Scientists to get it right. The one thing about calcium supplements that most Nutritionists agree, DO NOT JUST INCREASE CALCIUM BY ITSELF. Other minerals play vital roles. And to this should be added, take smaller amounts of calcium at one time.  ref   ref

This reference gives a great review of all the healthy bone building needed nutrients. ref

NOTE: The calcium recommended dietary intake, RDI, in the USA is between 1000 to 1200 mg. Since the absorption of dietary calcium has been found to be about 20-30 percent, this RDI would yield between 200-360 mg. One quickly sees that this may not keep pace with the amount eliminated in some cases. Another fact that needs to be addressed if these facts are indeed true, how do people in other Countries survive with stronger bones when the daily consumption is under 500 mg? A true Scientific dilemma, or are there other facts that play significant roles to protect bones and calcium not often acknowledged. 

HOW DID THE CALCIUM BONE RELATIONSHIP GET OFF ON THE WRONG FOOT SO EARLY?

Scientists looking at the bone fracture situation thought correctly that since calcium is one of the major components of bone, if bones are showing a calcium loss leading to reduced density and bone fractures, increasing calcium consumption should fix the problem.  Early research, especially sponsored by the Dairy Industry, revealed that this appeared to be a correct theory since bone density increased.

Here is where this early research failed. They assumed that this early increase in bone density would lead to the prevention of fractures later in life. BUT, they did not continue with long term studies to verify. Thus, calcium and bone science was based on only short term research assumptions. Now, some 70 years later, most longer term studies have consistently shown that these early assumptions were NOT EXACTLY CORRECT. Increased Dairy source calcium may actually generate more fractures over the long term, NOT LESS according to the Nurses' Health Study out of Harvard Medical. The next following articles will explain why. ref

**There is a need to balance the amount of calcium needed for bone protection against the other effects of calcium such as in cardiovascular health. What good is having strong bones when suffering from heart disease. A common sense position is needed overall for how much supplementation is healthy. The above reference lists the ideal calcium to magnesium ratio as 2.0-2.5. The final ratio may be closer to 1.7, but could depend upon overall diet as well. More on this later. 

Current trend in osteoporosis treatment is to increase bone building cells rather than just in the past to slow down bone tearing down cells. ref

Critical Note: No nutrient in the body operates in a vacuum. For proper calcium supplement amount, it is necessary to know some things about other related nutrients. Magnesium and calcium are linked together not only for bone building but also for cellular activities, especially in muscle and nerve functions. There is an ideal ratio (within 1.7 to 2.5***) balance point between calcium and magnesium for many normal body processes. Phosphorus and calcium also work together in bones. Vitamins A, C, D, E, and K perform actions to assist calcium pathways. 

***The trend to increase calcium supplements over the last two decades has increased the calcium to magnesium ratio to a point over 3.0. Above 2.7 and below 1.5, detrimental actions begin for those in the USA. Other Countries may have other challenge levels related to magnesium beginning levels and the current ratio number. Since both bone building as well as cardiovascular disease are involved, it is necessary to consider each when adding or decreasing calcium or magnesium supplement amounts for balancing ratio. It is possible for CVD risk to go up as bones gain density. It is the other related nutrients that can play vital protective roles here, especially vitamin K2.