Calcium and Osteoporosis

Barrie Carlsen

The Calcium Wars:

Over the years, there have been many "leading edge" calcium supplements to come to the market with the promise of preventing or reversing the growing incidence of osteoporosis. During the 1950's, dolomite was the wonder form of calcium which was purported to provide the body with both calcium and magnesium in a highly bio-available form. Dolomite is another name for limestone, which is the fossilized form of the shells of ancient marine creatures. Dolomite happens to be in the ratio of two parts calcium to one part of magnesium and the popular 2:1 ratio of Ca and Mg became the de-facto standard because the promoters of dolomite made unjustified claims that this ratio was 'natural' and therefore best for human needs. There was never any scientific validation that this 2:1 ratio was ideal for human needs. Even to this day, many supplement manufacturers promote the 2:1 ratio as the 'natural' ratio for human needs. An examination of the food composition table below shows that in the vast majority of common foods, magnesium content is greater than calcium. At about the same time bone meal supplements also became popular and the promoters promoted bone meal as being more ideal because it was more 'natural' than dolomite. Bone meal contains about 39% calcium and 55% phosphorus with almost no magnesium. Bone meal became the rival calcium supplement to dolomite. Both camps had their 'experts' as to why a particular form was best. Both forms however lost favour by the 1980's when it was discovered that both bone meal and dolomite often contained lead and other heavy metal contaminants.

Replacing dolomite was oyster shell calcium, which was virtually identical to dolomite, but was looked upon as being safer because it contained no lead. In the 1990's coral calcium became the new 'wonder' calcium supplement. Coral calcium was, and still is, promoted as a wonder nutrient but in reality it is just another form of inorganic dolomite and is not supported by any scientific studies to support any of the outrageous claims made for it. In the late 1990's calcium hydroxyapatite (HA) became the 'safer' form of bone meal because it is purported to come from cattle that are free from heavy metal toxicity. Again, many unsubstantiated claims are made for HA as a superior form of calcium supplementation and the 'war' between coral calcium and HA continues with 'experts' on both sides bashing the other.

While the calcium wars raged in the health food industry, the pharmaceutical industry was promoting purified calcium carbonate, calcium citrate, calcium lactate and other calcium supplements as the ideal forms of calcium supplementation and the dairy industry was heavily promoting milk and other dairy products as the ideal calcium source.

With doctors recommending that everyone should drink lots of milk and take at least 1000mg of a calcium supplement daily to create strong bones, and the health food industry promoting oyster shell, coral calcium and HA for the same reason, one would expect that there would be a decrease in North America of osteoporosis, given that millions of people drink milk and take these supplements daily on advise of their doctors. In reality, there is an epidemic of osteoporosis with a 7-fold increase in the last decade alone. (1) Clearly something is wrong. If milk and calcium supplements were effective in stopping osteoporosis then a slowing down or even reversal of osteoporosis should be evident rather than a 7-fold increase.

Our understanding of the role of calcium supplementation and osteoporosis is flawed. Many questions must be asked and the right answers must be found.

Which is the best form of calcium supplementation?

One must look at diet as the first step in understanding this question. For millennia mankind has obtained calcium and other minerals from diet alone, but it is only recently that osteoporosis has become a significant problem. It seems logical that a natural diet provides all the nutrients necessary to maintain strong bones and overall good health. Industrialization has created a whole new way of eating as urbanization has become the way of life for millions. Processed foods and more recently fast foods have become the new diet, and the increase of degenerative disease is related to these new dietary norms. Primitive man did not eat 'rocks' or 'bones' yet had strong, osteoporosis-free bones. The idea of ingesting bones, dolomite, oyster shell or coral is unnatural. These are inorganic substances and there is not another life-form on the planet that ingests them. One only has to watch a seagull eating oysters to gain an insight into nature at work. The gull frees the oyster from its mooring and lifts it high in the air then drops it to the rocks below, which fractures the oyster shell allowing the gull to feed on the meat inside. The gull, with one of nature's strongest digestive systems, is unable to use the shell and it is left behind along with billions of other shells to form future dolomite deposits. Coral calcium is another similar story. No creature in the sea ingests the coral, and left to nature the coral reefs will form future limestone deposits. Bone meal presents a similar picture. Not even vultures or hyenas will eat bone. One only has to wander the North American desert to see the bones of long dead cattle or buffalo, bleached white by the sun and providing no 'food' to any creature. Likewise a visit to a museum can show dinosaur bones which have become fossilized over millions of years. Even prehistoric life forms had no use for bones. Bone meal is to a mammal as the shell is to the oyster, the inorganic material which provides structure or shelter. Both are inorganic. In summary, there is no precedent in nature to use these inorganic and indigestible materials as food or medicine for man or any other mammal. Indeed regular consumption of these inorganic forms of minerals can cause severe health problems. In the case of HA there is even a defined medical condition, calcium hydroxyapatite crystal disease (2). This is a condition where deposits of un-dissolved crystalline HA accumulate in the joints giving rise to inflammation and pain. HA crystals are also linked to breast cancer (3). What then is the best form of calcium? A well balanced diet is obviously the best form of calcium and all other minerals and nutrients, as the minerals in food are organic and are easily bio-available to the body through normal digestive processes. If a supplement is required, then a mineral that most closely resembles the form which is found in food is ideal. The closest mineral supplement to the ideal is the amino acid chelate form of mineral (4). This is a special process where the mineral is ionized then attached to an amino acid forming a bond much like that found in a plant. This is the form most efficiently used by the body and it is the safest form with no known side effects.

What about milk? is it not natural and a real food?

Of course milk is a real food provided by nature to nourish the new-born for the first part of life. Milk provides specific nutrients and hormones to allow the new-born to develop rapidly, and the young is weaned from milk when it has completed its first cycle of development. One only has to look at a cow in its natural state to see that after weaning it grows to be a large and powerful animal eating only grass. It is only man that uses the milk of another species and feeds it to its youth and adults. When the natural diet of man is tampered with, then there will be predictable consequences. Milk consumption is related to the incidence of osteoporosis; all epidemiological research has shown that in those populations that consume the most milk, the incidence of osteoporosis is the highest. From these studies it is evident that milk consumption is not necessary to prevent osteoporosis, indeed it is likely to be one of the causative factors in the development of osteoporosis.

What co-factors are involved with calcium absorption?

In addition to bone health, calcium is needed for numerous bodily functions. When calcium blood levels are low, the body draws calcium from bones to support other important functions such as nerve impulse transmission, muscle contraction and blood clotting. When calcium is not available for bone formation, it results in reduced bone density and increased bone brittleness, which can increase the risk for fractures as well as for osteoporosis.

Other nutrients such as boron, silica, magnesium, potassium, phosphorus, vitamins D & K and zinc are also important to bone health, and some formulators have added various combinations of these co-factors to calcium formulas. By doing so they are attempting to deal with a dilemma of calcium fortification: Supplementation with only pure calcium can create a mineral imbalance and stimulate leaching of magnesium, potassium and other minerals from bone, causing hyper-mineralization of calcium and bone brittleness(5). Healthy bones and soft tissues need calcium in concert with magnesium, silica, phosphorus and other minerals and vitamins if they are to grow and develop normally over a lifetime.

Is calcium deficiency the real cause of osteoporosis?

The average daily intake of whole food is 1000 grams with an average of 2 calories per gram to provide a 2000 calorie per day diet, necessary to maintain ideal weight for the average person.

Calcium content (non-fortified) of some popular traditional Western Foods
(USDA Nutrient database)

FOOD

Calcium/Mg
per 100g

Calories
per 100g

Grams of food
per 1000mg of calcium

Calories
per 1000mg of calcium

Almond, raw

248/275

578

403

2,329

Peanut, Spanish, raw

106/188

570

943

5,375

Walnuts, English, raw

98/158

654

1.020

6.673

Potato, baked with skin

18/30

97

5,556

5,389

Carrot, raw

33/12

41

3,030

1,242

Spinach, raw

99/79

97

1,010

980

Beet greens, raw

117/70

22

855

188

Peas, green, raw

25/33

81

4,000

3,240

Corn, sweet, white, raw

2/37

86

43,000

36,980

Tomato, raw

13/10

23

7,692

1,769

Lentils, cooked

19/36

116

5,263

6,105

Soybeans, raw

197/65

147

508

746

Soybean, raw, sprouted

67/72

122

1,492

1,821

Soybean, mature, boiled

102/86

173

980

1,696

MOR-NU tofu, silken, firm

32/27

62

3,125

1.937

Apples, raw, with skin

6/5

52

16,667

8,667

Orange , raw

40/10

47

2,500

1,175

Orange juice, raw

11/11

45

9,091

4,091

Banana, raw

5/27

89

20,000

17,800

Strawberry, raw

21/17

69

4,762

3,286

Beef, sirloin, raw

24/21

201

4,166

8,373

Chicken, broiler, raw

13/25

319

7,692

24,538

Pork sausage, raw

9/14

304

11,111

33,778

Egg, whole, fresh, raw

53/12

147

1,887

2,774

Salmon, Chinook, raw

26/95

179

3,846

6,685

Tuna, bluefin, raw

8/50

144

12,500

18,000

Shrimp, raw

52/37

106

1,923

2.038

Wheat germ, crude

39/239

360

2,564

9,320

Rye flour, dark

56/248

324

1,786

5,786

Pasta, cooked without egg

6/14

124

16,667

20,667

Cream of wheat, prepared

64/6

62

1,562

969

Rice, brown, cooked

10/44

111

10,000

11,100

Rice noodles, cooked

4/3

109

25,000

27,250

Milk, raw, 3.25% milk fat

113/10

60

885

531

From the above table, it can be seen that it would be almost impossible to obtain 1000 mg of calcium daily from a 2000 calorie per day mixed diet if it included animal products, but did not include dairy products. Even if one were to have a diet exclusively of almonds, one of nature's richest non-dairy source of calcium, it would be impossible to obtain 1000mg of calcium daily if calories were restricted to 2000 per day. The whole idea that one must obtain 1000mg of calcium or more daily is simply marketing hype of the dairy industry to promote the consumption of dairy products as necessary for good health and strong bones. This blind acceptance of the dairy lobby's marketing hype by the medical association and public health authorities has led to millions of premature deaths and untold suffering

With a well balanced mixed diet that keeps animal protein to a minimum, the average daily intake of calcium is approx. 500mg per day. This is 'not coincidently' the average amount of daily calcium in the diet of the Okinawa people, who have been shown to have the longest life expectancy and the lowest rate of degenerative disease including osteoporosis in the world (6).

It seems evident that calcium deficiency is not the prime cause of osteoporosis, especially in a normal diet that supplies 500mg or more of calcium daily. To gain a deeper insight into the root of osteoporosis we must look at the modern Western diet for clues. Processed foods, especially refined grains are generally deficient in magnesium and silicon. Both magnesium and silicon are essential for proper bone health development and a deficiency of either one will cause poor bone development.

Magnesium supplementation reduces bone loss

It is generally assumed that an adequate calcium intake is essential in promoting the achievement of peak bone mass in growing children and young adults. Now researchers at the University of Graz Medical School in Austria and the Loma Linda University in California suggest that an adequate magnesium intake may be equally important. About half the body's reservoir of magnesium is found in soft tissue while the other half is found in bone. Excess magnesium is excreted in the urine. The researchers recently completed an experiment in which 12 healthy, young men received 350 mg of magnesium as a daily oral supplement for a 30-day period. A comparison of the level of biomarkers for bone turnover in the supplemented group and in an age-matched control group showed a statistically significant decrease in the level of these biomarkers in the supplemented group. Neither the supplement group nor the control group were deficient in magnesium and had a dietary intake of about 300 mg/day (RDA is 300-350 mg/day). The researchers conclude that magnesium supplementation (over and above the current RDA) may suppress bone turnover in young adults and speculate that it may also help prevent age- related osteoporosis. (5)

Silicon and Bone Formation

The importance of silicon for structural strength in plants has been fairly well known, researched and demonstrated, and indeed one of the first supplementary forms of silicon was from the horsetail plant. Silicon forms app. 28% of the earth's surface, and it is present in clay, sand, rocks, sea water, and as mentioned, in the fibers of plants. This latter, however, assumes the presence of silicon in the soil which grew the plants.

In the 1970s, some interesting research with animals brought to light a possible connection between inferior development, structural abnormalities, and poor cartilage and bone structure in animals receiving a diet deficient in silicon. Drs. Carlisle & Schwarz found that chicks and rats on a silicon deficient diet were smaller and developed severe skeletal malformations which were preventable with silicon supplementation. That this would also be relevant to humans was hinted at by a discovery of Mourkazel in 1992 that pediatric patients fed parenterally showed a decreased serum silicon concentration coincident with decreased bone mineral content.

In the United States , the mean daily silicon intake is between 20 and 50 mg (established by Pennington in 1991), a figure which is considerably less in this era of refined foods, where the removal of the plant and grain fibers from the diet has lowered the silicon content. The largest sources of dietary Si are grains, beverages (particularly beer) and vegetables. Dairy foods, poultry, fish and meat contain relatively little of the element.

The human body contains app. 7 grams of Si, with the serum content ranging from 0.2 to 4.0 ppm. (Bercowy, 1994)

The 1970 experiments of Carlisle & Schwartz found a correlation between the amount of Si in the diet and the mineralization level of the young bone. Si was found to be located uniquely in the areas where active growth was taking place, declining in relationship to the laying down of hydroxyapatite, or bone crystal, which is the process that transforms young, pliable bone into a hard, calcified structure. This led the Doctors to hypothesize that Si acted as a regulating factor for the deposit of bone.

The process of bone adsorption and formation is at all times dynamic. Osteoporosis occurs when the rate of bone breakdown by osteoclasts outpaces the rate of bone building by osteoblasts. A 1993 study done in Paris by Dr. Marie dealt with Si supplementation in estrogen deficient rats. The ovaries were removed surgically, and true bone loss was observed both as loss of bone volume, and an increase in osteoclasts as compared to controls. One finding was that Si supplementation significantly reduced the rate of bone loss, from 48% in un-supplemented rats to 34% in those receiving Si.

In another French study, 8 osteoporotic women received bi-weekly injections of 50 mg of Si twice a week for 4 months. The bone mineral density of the femur increased by 4.7% over the course of the treatment. ( Eisinger et al, Magn. Res., 6, 1993)

As well as these two in vivo studies, in vitro results have also been suggestive of an important role for Si in bone remodeling. Dr. Riggs et al (Mayo Clinic, Rochester ) showed that a silicon containing compound stimulated the DNA synthesis in osteoblast-like cells, at the same time inhibiting osteoclast mediated bone resorption.

The need to revise the RDA for Calcium

In summary, it can be seen that the present RDA for calcium requirement is based on the influence of the dairy industry. An examination of the food table clearly shows that magnesium is more dominate than calcium in a non-dairy based diet. The RDA for magnesium is 300-400mg per day, and in a natural diet, the RDA for calcium should be about the same or slightly less. This explains why the Okinawa people have little osteoporosis with about 500 mg per day of calcium (1998 Okinawa Prefecture Health and Nutrition Survey), and the mostly vegetarian Bantu of Africa have no osteoporosis with about 300mg of calcium per day from a diet completely free of dairy foods. The diet of both the Okinawa 's and the Bantu is rich in bone building magnesium and silica because they eat almost no refined foods. Osteoporosis is much less common in China even though calcium intakes are much lower (7). Contrast this with North Americans, who live on a high-protein diet, have the greatest calcium intake and the lowest magnesium and silica intake of any population, yet they also have one of the highest rates of osteoporosis. The level of dairy product consumption in the United States is among the highest in the world but osteoporosis and fracture rates are also among the highest. (8)

It is impossible to obtain 1000mg of calcium a day from a 2000 calorie per day mixed diet that does not include dairy, much less 1500mg per day which is recommended for post-menopausal women. The scientifically unfounded RDA's for calcium is an economic one designed to promote dairy consumption, and its spin-off industry the promotion of calcium supplements. If it were true that 1000-1500mg per day of calcium is necessary to prevent osteoporosis, then almost all vegetarians would have osteoporosis and milk drinkers would be free from the disease. In the real world just the opposite is true.

Men and calcium: A cautionary note

Calcium is usually talked about in connection with women and osteoporosis (80% of osteoporosis sufferers are women), but more than a dozen studies show a link between a high-calcium diet and prostate cancer. In one of the largest, scientists at the Harvard School of Public Health studied the diets of 20,885 male physicians to tease out the relationship between dairy products and prostate cancer risk. Their results, published in the October 2001 issue of the American Journal of Clinical Nutrition, found that men who consumed more than 600 mg of calcium per day had a 32% increased risk of prostate cancer compared with those who took in less than 150 mg per day. The authors concluded high calcium intake, mainly from dairy products, may increase prostate cancer risk by lowering concentrations of 1,25-dihydroxyvitamin D3, a hormone thought to protect against prostate cancer. For each additional 500 mg of calcium from dairy products per day, researchers saw a 16% jump in the men's prostate cancer risk. There's a general message that the more calcium the better, says June Chan, the study's lead author. That's not necessarily the case, especially for men.

Even more surprising were results from a 1998 study that traced the health of 50,000 men. The researchers found that those men who were avid calcium consumers (more than 2,000 mg per day) had a nearly fourfold increase in the incidence of prostate cancer over their calcium-shirking counterparts (500 mg or less a day).

What about Ipriflavone?

For years, estrogen replacement therapy was the drug of choice for treatment of osteoporosis in postmenopausal women. But the potential risks of HRT sent women searching for alternatives. One option was phytoestrogens - plant-based compounds that bind to estrogen receptors in the body, presumably mimicking the beneficial effects of estrogen without its potential risks. Of the phytoestrogens, the most promising was ipriflavone, a synthetic version of a naturally occurring isoflavone, a type of phytoestrogen.

But a well-designed study published in the March 21, 2001 Journal of the American Medical Association refutes the positive results of previous studies, demonstrating that ipriflavone does not prevent bone loss or reduce the risk of fracture in postmenopausal women. It also cautions that ipriflavone lowers levels of lymphocytes, an effect that could make women more vulnerable to infection.

In the JAMA study, members of the Ipriflavone Multicenter European Fracture Study Group assigned 474 postmenopausal white women with low bone mass aged 45 to 75 to either 200 mg of ipriflavone taken three times per day or a placebo, for the three-year duration of the trial.

At the end of the trial, the researchers found no significant difference between the treatment groups in regard to bone mineral density measured at the lumbar spine, total hip, and distal radius; in biochemical markers of bone formation or bone resorption; or in the number of vertebral fractures suffered by the women.