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Calcium for Strong Bones
The Benefits of Calcium
By: Dr. Obikoya
Calcium is the mineral most likely to be deficient in the
average diet. Let me repeat that. Calcium is the mineral most likely to
be deficient in the average diet. Calcium deficiency is a condition in
which we fail to receive or to metabolize an adequate supply of Calcium. Calcium
is the chief supportive element in bones and teeth. Calcium salts make up about
70 percent of bone by weight and give your bone its strength and rigidity.
About 99 percent of the calcium in the human body is held in the bones and
teeth. The remaining 1 percent of calcium circulates in the bloodstream, where
it performs a variety of important functions. It helps to contract muscles and
helps regulate the contractions of the heart. It plays a role in the
transmission of nerve impulses and in blood clotting. Calcium is involved in the
stimulation of contractions of the uterus during childbirth and in milk
production. It also regulates the secretion of various hormones and aids in the
functioning of various enzymes within the body.
When we take Calcium, it absorbed in the small intestine and passes from there
either into the bloodstream or ultimately into the bones. The most efficient
absorption of calcium is dependent on the presence of vitamin D in the body,
which is a key ingredient in the various hormones that enable calcium to pass
from the digestive system into the blood or bones. Similarly, there are optimal
ratios of phosphorus to the amount of calcium consumed that permit calcium to be
more completely utilized. Hormonal secretions of the parathyroid and thyroid
glands (parathyroid hormone and calcitonin, respectively) also help maintain
calcium equilibrium in the blood.
These regulatory mechanisms help to prevent a deficiency in calcium from
developing in the bloodstream. When such a deficiency does develop, parathyroid
hormone acts to transfer calcium from the bones in order to maintain the
mineral's all-important presence in the bloodstream. This of course strips your
bones of their calcium and in turn weakens your bones, making them more brittle
and subject to breaking.
The result of a mild insufficiency of calcium over the long term may be thinning
bones, termed osteoporosis or the softening of bony tissue, called osteomalacia.
The faulty metabolism of calcium during childhood may result in a condition
called rickets.
Recent research even points to calcium deficiency as being a possible cause of
hypertension (high blood pressure) and of colon cancer.
Severe calcium deficiency, which is defined as a reduction of calcium levels in
the bloodstream below a certain normal range, has its own clinical
manifestations. The main syndrome is tetany, which involves sensations of
numbness and tingling around the mouth and fingertips and painful aches and
spasms of the muscles. A clinically detectable deficiency of calcium is a
relatively rare finding and is almost always caused either by a deficiency of
parathyroid hormone or of vitamin D in the body, the two chief regulators of
calcium metabolism. Usually the problem manifests as an insidious, low level of
calcium over a long period of time, which is far more difficult to correct.
You’ve heard it now and probably many times before. You need calcium to
prevent osteoporosis. But a lack of this mineral means more than weak bones. Key
organs and bodily functions, like your heart and metabolism, need calcium to
operate at their best. Yet only 21 percent of us are getting the recommended
amount of calcium, according to federal government statistics.
Here are five important but little-known ways that getting more calcium can
improve your health:
Calcium helps keep the weight off. Research suggests that if you don't get
enough calcium in your diet, you're likely to be overweight. Of course, it's
possible to be overweight even if you do get plenty of calcium, but an adequate
supply of Calcium appears to make it easier to maintain a healthy weight. The
reason has to do with your body's response to a calcium deficit. When you're
low, your body thinks you're starving and enters emergency mode, releasing
parathyroid hormone from four glands in your neck. This hormone stimulates your
bones to release some calcium into your bloodstream. Your kidneys also deliver a
dose of a hormone called calcitriol, a form of vitamin D, to increase your
ability to absorb calcium. This helps keep the body in balance, but is operating
the body in an emergency mode, which over time, is very unhealthy.
The trouble is that parathyroid hormone and calcitriol also stimulate the
production of fat and inhibits its breakdown. As a result, your body stores fat
and holds on to it stubbornly, even if you're on a low-calorie diet. On the
other hand, a high calcium intake suppresses these hormones so your body stores
less fat and also breaks it down far more easily.
Calcium also protects your heart. If you're low on calcium, you're more likely
to have high blood pressure. Your body releases the hormone calcitriol in
response to a calcium shortage, and calcitriol acts on the smooth muscle walls
of your arteries, constricting them and elevating your blood pressure. In fact,
your calcium intake may be almost as important to blood pressure as your
sodium intake. An adequate supply of calcium helps muscles, including
your heart muscle, do their work of contracting and relaxing. Calcium also
appears to help your nervous system regulate the level of pressure in your
arteries.
Calcium improves premenstrual moods. Getting enough calcium can ease the
symptoms of premenstrual syndrome (PMS). The explanation comes down (again) to
calcium-regulating hormones. Your body suppresses the hormones if your calcium
supplies are adequate, but releases these hormones if you're not getting enough.
Women who suffer from PMS appear to have elevated levels of these hormones
during their menstrual cycle, which account for the symptoms of PMS, like
cramping, irritability, and depression, are similar to the symptoms of a
calcium-deficient state.
Calcium protects against colon cancer. Adequate calcium intake may reduce your
overall risk of colon cancer and suppress the growth of polyps that can lead to
cancer. Researchers don't know exactly why this happens, but it may be linked to
the excess calcium that's left in your intestines after your body absorbs what
it needs. On its way through the colon, this unabsorbed calcium is believed to
bind with cancer promoters so they're excreted together from the body. Studies
have shown that both food sources of calcium and calcium supplements provide
this protective effect.
Calcium maintains healthy teeth. Calcium protects your teeth in an indirect way.
Your teeth themselves are relatively inert, meaning that the calcium they
contain usually stays there. Your jawbone is the potential problem. Like other
bones, it gradually surrenders calcium for needs elsewhere in your body if
you're not consuming enough. As your jaw weakens, your teeth loosen, creating
gaps where bacteria can invade, triggering infection, inflammation, and
bleeding. In fact, the condition of your teeth and gums can be a window to the
overall health of your bones. Not surprisingly, the first signs of osteoporosis
are sometimes found by your dentist.
Talk to your health care practitioner if you experience the unexpected loss of a
tooth or your teeth start to feel loose. Sufficient calcium intake can prevent
these problems in the first place, as well as help guard against a whole host of
other problems.
References
National Osteoporosis Foundation. Osteoporosis: review of the evidence for
prevention, diagnosis, and treatment and cost-effectiveness analysis. Osteoporos
Int. 1998; 8(suppl):S7-S80.
NIH Consensus Development Panel on Optimal Calcium Intake. Optimal Calcium
Intake. JAMA. 1994; 272:1942-1948.
Morgan SL. Calcium and vitamin D in osteoporosis. Rheum Dis Clin North Am. 2001;
27:101-130.
