Supplements have a major flaw. This flaw is also found unfortunately in some nutritional information. It concerns how much of a particular nutrient is needed to be consumed daily. Let's look at calcium to discover how this flaw might have developed. Scientists measured the amount of calcium people excrete out each day in Developed Countries. This usually is an average about 350 mg, but many mechanisms influence this number. This number includes some calcium that was previously re-absorbed back into the body, so it is not all from the calcium consumed that day. This amount could be up to 250mg, so the needed dietary intake amount would be reduced.
Since calcium absorption can vary from 10-50%, the average is about 33% making the daily requirement 3.3 X 300-400, or 1000 to 1200 mg. This also includes an amount for an extra margin of safety. Plus, the Professionals look at how much is in the body and what is happening to bones. But, there is more to the story that just elimination or bone density, especially since the body recycles calcium. Read this reference for complete info.
Thus, the question that has to be answered is this: How do people maintain bone strength in Countries where only 300 - 400 mg of calcium is consumed daily? And the people have stronger bones with less fractures than here in America.
It is not only how much the typical diet contains of calcium, but what happens in the body to either hold and recycle or eliminate calcium. And, there are other nutrients or conditions that interact to change these recycled or eliminated amounts. These include dietary amounts of sodium, protein, body pH levels, and degree of movment or exercise. Plus, whether or not the body needs calcium at that moment as determined by blood levels. With calcium, the body has very elaborate processes to recycle, store, assimilate or eliminate calcium to control this blood level at just the required level. The true driver of calcium behavior, absorption, and elimination is blood levels not bone density. Hormones are very involved here. Primarily estrogen which may explain why women need slightly more calcium than men. Some people have strong bones on little calcium intake while others have weak bones consuming lots of calcium. ref Thus, just looking at calcium alone is not enough. Or just adding extra calcium does not always result in stronger bones, even though bone density is increased. And this is also why using averages does not work for all people.
Concentration Concerns
Some Supplements are too concentrated for the body to process in a normal matter without impacting other nutrients. In plant foods, minerals are found with fibers that limit the absorption rate. In foods like milk, Calcium is readily absorbed with only fats and proteins to slow absorption. ref Calcium carbonate supplement has the highest percentage of calcium making it the obvious choice of many consumers who dislike taking so many pills. But, consuming a high dose of calcium at one time not only decreases the absorption percent, it can spike calcium blood (plasma) levels with resulting possible adverse consequences as copied below from reference:** ref
"Sodium ion channels in the cell membranes of nerves and muscle are particularly sensitive to the calcium ion concentration in the plasma.[4] Relatively small decreases in the plasma ionized calcium levels (hypocalcemia) cause these channels to leak sodium into the nerve cells or axons, making them hyper-excitable (positive bathmotropic effect), thus causing spontaneous muscle spasms (tetany) and paraesthesia (the sensation of "pins and needles") of the extremities and round the mouth.[5] **When the plasma ionized calcium rises above normal (hypercalcemia) more calcium is bound to these sodium channels having a negative bathmotropic effect on them, causing lethargy, muscle weakness, anorexia, constipation and labile emotions.[5]"
WHAT IS NEEDED IS AN OPTIMAL CONSUMPTION AMOUNT OF CALCIUM WITHOUT GOING TOO LOW OR TOO HIGH OVER THE LONG TERM. On cardio- ref A variety between High and Low calcium intake days is really OK and actually beneficial if balance points are maintained long term. The long term approach in the U.S. has been to error daily on the side of consuming extra calcium which now according to ongoing longer term research studies may NOT ALWAYS BE HEALTHY for bones, heart, or prostate and some other related issues. To continue enriching so many foods with calcium and taking extra in supplements is .....perhaps not wise unless the total picture is known.
CALCIUM IONS ?
If you noticed in the above copy, the effects were related to levels of calcium IONS in blood plasma and not just overall calcium amounts. Some calcium is bound to proteins and some calcium exists as free ions. There is a difference to the body. It is the amount of calcium ions that trigger body actions to balance blood calcium. ref
From last reference- "PTH increased by 400% within 10 minutes in response to decreased ionized calcium"
How does the body regulate the balance between the two forms? Besides albumin protein binding levels, turns out the pH or chemistry of the blood also influences ion amounts. Lower blood pH, indicating higher acids, increases calcium ions, probably by changing protein binding attraction. Maybe there is more to the pH story and what you eat does make a difference. ref Calcium ions have a normal level that is almost half the total blood calcium amount. The very elaborate body process mentioned above involves: Parathyroid gland PTH hormone, Kidneys, Liver, Bone storage or release of calcium, pH regulation, thyroid gland, and the intestinal tract, all to help maintain this critical calcium ion balance.
Men Only
Of special interest is that in men, high normal range blood calcium ions (ionized calcium) levels are associated with increased risk for prostate problems. Here are some factors to consider from a dietary perspective. 1. Increase fluid intake, mainly water or non sugar drinks, but not sugar-free sodas. Dehydration increases calcium concentration in blood. Your Kidneys function to control calcium levels. 2. Limit vitamin D intake. 3. Limit calcium containing foods, I.e. dairy, and calcium supplements. Dairy also increases phosphates just like some Colas. 4. Be physically active. And 4. Visit your MD to monitor functions of the above mentioned organs, glands, and hormones. ref
Women Only Mostly
Women may need slightly more calcium. Since the daily requirement for calcium is 1000 to 1200 mg, first one has to consider how much the diet contains and then add in supplements to get up to 1000 or 1200. Average American diets supply 648-968 mg of calcium. Yes some people consume less. Each serving of dairy adds 300 mg, so dairy consumers may only need to supplement magnesium to help balance food calcium back to 1.5 -2 to 1 balance over magnesium. This means calcium supplements only up to 600 mg are on average needed. Plus, as you explore the many articles on this website, there are many misconceptions about the role and amount of calcium and/or vitamin D play in bone health. They are just two of many factors to consider. Read these articles article and article.
VITAMIN D & K on Calcium
Problems develop when supplements of just calcium are consumed without supporting bone building and calcium requlatoring cast members. Vitamin D directs the production of osteocalcin which when activated by vitamin K2 binds calcium into bone crystals. Vitamin D also regulates calcium assimilation, plus it also participates in immune system activities through the direction of CD44.
NOTE: Vitamin D and osteocalcin levels are often not directly related since many other conditions like inflammation or other nutrient levels like magnesium can also influence.
Vitamin K2 also acts on a protein, Matrix GLA, in the arteries that prevents calcium binding into the artery wall. ref Both vitamin D and vitamin K have been decreasing in the diet and through limiting sun exposure since1950's.
FYI: These same nutrients also participate in regulating blood sugar levels adding to their benefits as well as importance of ratios and balance to maintain one function without jeopardizing another.
Clarification of MEAT (protein) ON CALCIUM LOSS
Many early studies found that when people consume meat, there is more calcium eliminated in urine. The thought process behind this observation was that meat generated acid in the body and the body responded by removing calcium from bones to neutralize this meat generated acid. This would weaken bones over time. The body wants to use potassium from vegetables and fruits to neutralize acid, so the Scientists next added a potassium salt with the meat diet to attempt to save calcium. But, still calcium was found in urine. It turns out the calcium increase in the urine did not come from bone, but was from the meal with the meat.
The next question to solve, what was neutralizing the extra meat acid if not calcium from bone, especially in people who did not consume many vegetables and fruits? It may be elements coming from muscle loss supplied the acid buffers. This changes quite a lot of past theories. One important aspect, it reveals why Americans may need higher calcium intake than in other Countries where less meat is consumed. Meat increases calcium absorption percent but also increases amount lost in urine.
This explains many controversial study results from the past. But, still shows higher vegetable and fruit intake or an alkaline diet still has value. Like maintaining muscle mass and bone integrity during the growing old process.