Calcium is traditionally used for preventing or treating
osteoporosis and prenatal nutrition during pregnancy, as well as high
blood pressure in salt-sensitive cases and pregnancy induced high blood
pressure.(1)
Calcium supplementation addresses osteoporosis
prevention and treatment. Remodeling imbalance presents a wider
therapeutic issue that mineral supplementation cannot in itself address.
However, achieving optimal mineral conditions is a critical step.
Other factors like lifestyle or hormonal therapy will address emodeling
imbalance.
All calcium deficiencies if uncorrected will lead to bone disorders,
especially in growing children, but not all cases of osteoporosis are the
direct result of dietary calcium deficiency. Other considerations are
important beyond calcium, and life style is central. The typical North
American diet has the potential for causing excessive bone calcium
"mobilization" that can lead to calcium wastage via urine excretion. High
phosphate intake via meats and soft drinks, high sugar intake, and
excessive plasma amino acid concentrations from excessive protein intake
call for calcium buffering, representing chronic drains on calcium bone
density.
Two other important lifestyle factors that influence the mineral density
of bones are exercise and smoking. Many adults who work in sedentary jobs
stop exercising in meaningful ways early in life. Yet, daily minimal
weight-bearing exercise is able to drive bone formation, assuming dietary
needs are met. Smoking is thought to ultimately lead to the potential for
lower blood pH due to compromised CO2 venting in the lungs, thus allowing
higher levels of carbonic acid to accumulate in the blood. Accordingly,
more bone minerals will be mobilized to buffer the blood.
Calcium might be the mineral that gained the greatest recognition and
acceptance. We are constantly advised to take calcium, in order to have
strong bones, and the acquired bone density needed for our latter years to
avoid bone fractures due to osteoporosis. Osteoporosis concerns are well
founded in North America, where approximately 1.3 million women suffer
fractures each year as a result of osteoporosis. And to add concern, the
rate of osteoporosis fractures has been gong up over the past three
decades in a manner that cannot be fully explained simply by the increase
in an aging population.(6)
Part of the problem in curbing the incidence of osteoporosis is a
widespread singular focus on calcium, with little or no emphasis on
magnesium and vitamin D, and often only lip service to other critical
mineral factors and meaningful exercise.
Avoiding osteoporosis is much more complex than simply increasing calcium
intake, or even relying on appropriate supplementation alone. Exercise and
meaningful reductions in calcium wastage are central to maintaining
optimal conditions for arresting bone decline. It is important to realize
that osteoporosis is an infrequent disease in the so called third world,
where calcium supplementation, and milk consumption for that matter, is
virtually non-existent and daily dietary calcium intake is typically below
the average intake of North Americans.(6) However, the level of
weight-bearing exercise is consistently higher.
As much as 50% of the body's magnesium is found in the bones, pointing to
the importance of magnesium to bone health. Calcium is the central mineral
in bone mineralization or calcification, but the quality of the calcium
crystals formed is dependent on magnesium. When too little magnesium is
available, the calcium crystals are at risk of being irregular in size and
shape, forming weaker bones and permitting fractures to occur, even when
consistent efforts have been made to consume the recommended daily calcium
supplements.(7) Magnesium also provides a general alkalizing effect on the
body's pH thus helping to avoid the need to sacrifice bone calcium as a
buffer.
Vitamin D performs three indispensable functions in developing and
maintaining bone mineral density: 1) It facilitates dietary or
supplemental calcium absorption from the intestines; 2) It decreases
urinary calcium losses due to normal kidney filtration; and 3) It
facilitates the incorporation of calcium into the bones. Even a subtle
protracted deficiency of vitamin D leads to increased risk of bone loss
over time and osteoporosis fractures.(15) Numerous studies document that
up to 80% of all hip fracture patients may exhibit vitamin D
deficiency.(16) There is a growing clinical recognition of vitamin D
deficiency in the general population, leading to the conclusion that
current levels of so-called adequate intake are too low.(15,17,18)
Separate clinical investigations using 700 and 800 IUs instead of the
usual 400 IUs have demonstrated lower hip fracture rates compared to
placebo.(18) The omission of adequate supplemented vitamin D by those with
already thinned bones or full-blown osteoporosis is certainly a strategic
error in judgement. The margin of safety is substantial for vitamin D,
with toxicity being associated with a daily amount greater than 2400 IUs,
allowing an easy comfort level with 800 to 1000 IUs per day for adult
bodies.(18)
Other nutritional factors are known to participate in bone formation and
renewal, such as Vitamin K, Manganese, Folic Acid, Boron, Vitamin B-6,
Zinc, Strontium, Copper, Silicon, and Vitamin C. These can be obtained in
a diet of fruit and vegetables and whole grains, as well as supplementing.
Calcium supplementation has also been helpful in cases of salt sensitive
high blood pressure, as well as in pregnancy induced high blood
pressure.(1, 11,12)
In older osteoporotic patients with compromised fat absorption, the
optimal daily intake of fat soluble vitamin D should be clinically
determined to insure that disease modifying absorption of dietary calcium,
renal re-absorption of calcium, and vitamin D-dependent bone incorporation
of calcium is occurring.
Contraindications
If you
are suffering of hyperparathyroidism or cancer, you should not supplement
with calcium unless directed by a physician.
Those seeking to arrest or reverse osteoporosis should
be encouraged to supplement with magnesium at a ratio of 2 parts calcium
and 1 part magnesium. Magnesium appears to enhance calcium crystal size
and shape, beneficially influencing crystal strength, and therefore, bone
strength.(6)
A multi-mineral supplement in addition to calcium/magnesium
supplementation will provide other important minerals thought to be a part
of normal bone metabolism. These include manganese, copper, strontium, and
silicon. Boron and vitamin K cannot be supplemented in Canada but are key
nutrients profoundly relevant to bone health. However, both of these
nutrients can be supplied in a diet that emphasizes fruits and vegetables,
especially green leafy vegetables and apples, which can contain as much as
3 mg of boron in the apple skin. If this is unlikely to happen on a
consistent basis, regular use of a dehydrated plant food supplement should
be recommended. Boron depletion in postmenopausal women contributes to
urinary excretion of calcium and magnesium, and depressed serum
concentrations of estrogen and testosterone, both hormones being important
to bone remodeling.(1)
The following points indicate known interactions with calcium and other
minerals, but are not offered as an exhaustive list.
- Calcium absorption is dependens if adequate vitamin D is present. The
typical recommended daily intake is 400 IU for ordinary needs. Those who
are seeking to arrest osteoporosis should discuss with a qualified health
care professional for a dosage of 800 IU per day.
- Calcium as magnesium and other minerals combine with quinolones and
tetracyclines. If calcium is used together with these, the antibiotics
will be less effective. Minerals should be used at least two hours apart
from these antibiotics. If the antibiotics are used on a long term, they
may produce mineral deficiencies.(8)
- Loop diuretics may cause the loss of calcium and magnesium from the
body. Since many of those using loop diuretics could also be osteoporotic,
supplementation of these minerals may be necessary.(8)
- Minerals (like calcium and magnesium) loses, are also caused by thiazide
diuretics. If they are used for a long term, the human body can be
depleted of calcium, magnesium and other minerals. Many of the people that
are using thiazides can also be osteoporotic, therefore supplementation of
minerals may be necessary.(8)
- Calcium absorption is interfered by corticosteroids. If used on
long-term, may contribute to or exacerbate osteoporosis.(8)
- If taken within less than 2 hours, calcium and magnesium may interfere
with the absorption of etidronate (didronel). Calcium deficiencies may
result even because etidronate alters vitamin D metabolism.(8)
- Calcium interferes with iron absorption and this may be important in
premenopausal supplementation of calcium with only a multi-mineral
product, where calcium and iron are found in combination.(8)
- Vitamin D metabolism is altered by isoniazid and it is possible to
interfere with calcium absorption.(8)
- Also, doses of magnesium, fiber, zinc, and oxalates can interfere with
calcium absorption.(1)
- Alcohol, caffeine, protein (amino acids), sodium, sugar, and some of the
phosphates, contribute to calcium excretion.(1)
- High intake of calcium and vitamin D fortified dairy foods may decrease
magnesium absorption.(1) This is why it is wise to add magnesium to overt
calcium supplementation.
Calcium supplements are usually well tolerated in daily
dosages up to 2000 mgs. Higher intakes may contribute to kidney stone
formation and soft-tissue calcium deposits.(1,2) However, magnesium
supplementation reduces the risk for kidney stone formation, especially
magnesium citrate, increasing the solubility of calcium in urine
formation.(1,6) Using more than 2000 mg per day is unlikely to make a
significant clinical contribution unless deemed to be warranted by a
clinician.
The National Institutes of Health (NIH) in the United
States in their Consensus Statement on optimal daily calcium intake set
higher values than the RDA and gave more specific milligrams by age
groups. These are recommended and listed below.(14)
The NIH
Recommended Daily Elemental Calcium Intake
1. Murray, Michael T., Encyclopedia of Nutritional
Supplementation, Prima Publishing, Rocklin, CA, 1996
2. Whitaker, Julian, Dr Whitaker's Guide to Natural Healing. Prima
Publishing, Rocklin, CA, 1995
3. Editorial, Citrate for calcium nephrolithiasis, Lancet, I: 955,
1986
4. Teo, K.K., et al, Role of magnesium in reducing mortality in acute
myocardial infarction: A review of the evidence, Drugs, 46: 347-359,
1993
5. Turlapaty, P., et al, Magnesium deficiency produces spasms of coronary
arteries: Relationship to etiology of sudden ischemic heart disease,
Science, 208: 199-200,1980
6. Gaby, Alan R., Preventing and Reversing Osteoporosis, Prima Publishing,
Rocklin, CA, 1994
7. Cohen, L., Kitzes, R., Infrared spectroscopy and magnesium content of
bone mineral in osteoporotic women, Israel Journal of Medical Science, 17:
1123-1125, 1981
8. Graedon, Joe, Graedon, Teresa, Deadly Drug Interactions, St Martin's
Griffin, New York, 1995
9. Germano, Carl, The Osteoporosis Solution, Kensington Books, New York,
1999
10. Dawson-Hughes, B., et al, Rates of bone loss in postmenopausal women
randomly assigned to one of two dosages of vitamin D, American Journal of
Clinical Nutrition, 61: 1140-1145, 1995
11. Belizan, J.M., et al, Calcium supplementation to prevent hypertensive
disorder of pregnancy, New England Journal of Medicine, 325: 1399-
1405,1991
12. Knight, K.B., et al, Calcium supplementation on normotensive and
hypertensive pregnant women, American Journal of Clinical Nutrition, 55:
891-895, 1992
13. He, J., Tell, G., Tang, Y., et al, Effect of dietary electrolytes upon
calcium excretion: The Yi People Study, Journal of Hypertension,
10:671-76,1992
14. Optimal Calcium Intake, NIH Consens Statement Online, 1994, June 6-8;
12(4):1-31
15. Compston, J.E., Vitamin D Deficiency: time for action, editorial,
British Medical Journnal, 317: (Nov 28), 1466-1467, 1998
16. Brown, Susan E., Better Bones, Better Body, Keats Publishing, New
Canaan, CT, 1996
17. Thomas, Melissa K., Hypovitaminosis D in medical inpatients, New
England Journal of Medicine, 338:, 777-783, 1998
18. Utiger, Robert D., editorial, The need for more Vitamin D, New England
Journal of Medicine, 338:12, 828-829, 1998
These statements have not been evaluated by the Food and Drug Administration (FDA). Products are intended to support general well being and are not intended to treat, diagnose, mitigate, prevent, or cure any condition or disease. If conditions persist, please seek advice from your medical doctor.
