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Calcium and magnesium are essential minerals for good health, and we often hear about their benefits to our bones. But these vital nutrients are involved in many other body processes as well.

As the most abundant mineral in the body, calcium has a number of important functions. In addition to building strong bones and teeth, it strengthens muscle contraction, improves nerve transmission and blood clotting, regulates heart beat, and activates enzymes.

Magnesium, calcium’s companion, is required to form bones, proteins, and fatty acids, relax muscles and blood vessels, improve nerve transmission, activate B vitamins, clot blood, help in the secretion of insulin, and form the adenosine diphosphate that provides energy for body processes.

Calcium and magnesium are companion minerals because they work together, with magnesium regulating the transport of calcium through the body. The two minerals also balance their effects within the body, with magnesium relieving the constipation that calcium causes in some people.

Calcium’s Contribution

We know that calcium is important in the prevention and treatment of osteoporosis. Calcium supplements have been shown to increase bone density and reduce fractures. For osteoporosis treatment, most doctors recommend 1,500 to 2,000 mg daily.

Studies of women with PMS show that 1,200 mg calcium, taken daily, can significantly reduce symptoms of negative feelings, anxiety, water retention, food cravings, and pain.

Calcium is also important for women in pregnancy, as it is used to prevent pre-eclampsia—a condition of high blood pressure, swelling, and loss of protein in urine.

Other studies have shown that high calcium intake at 1,500 mg per day can lower blood pressure.

Calcium can be depleted by high sodium, caffeine, and alcohol intake. A number of drugs, including antacids, anticonvulsants, estrogen, diuretics, and anti-inflammatory and cholesterol-lowering drugs, also deplete calcium. Signs of deficiency include weak bones, fractures, tooth decay, muscle cramps, palpitations, and nervousness.

Several forms of calcium are available, including carbonate, citrate, lactate, and phosphate. Calcium carbonate is usually recommended because this form has 40 percent calcium per tablet, is readily available, and is inexpensive. Calcium carbonate should be taken with meals in divided dosages—500 mg at a time—for maximum absorption. Calcium citrate can be used for the elderly and those taking acid-lowering drugs, who may not be able to absorb calcium as easily. This form provides 21 percent calcium per tablet.

Mighty Magnesium

In addition to its role in the formation of bones and other body processes, magnesium is used in the treatment of high blood pressure, arrhythmia, heart attack, angina, congestive heart failure, and mitral valve prolapse.

In the lungs, magnesium promotes relaxation of bronchial muscles, improving breathing and preventing spasms. Magnesium levels may be lower in those with asthma, and some research has shown benefits with supplementing.

Magnesium may be depleted in women with PMS, and studies have found supplements of 200 mg daily can help reduce the symptoms of fluid retention, weight gain, swelling of extremities, breast tenderness, and abdominal bloating.

Levels of magnesium may also be lower in those with chronic fatigue syndrome, ADHD, migraines, and diabetes, and supplementing may offer benefits for these conditions.

While serious magnesium deficiency is rare, marginal deficiencies are common today, primarily because of modern food processing and changes in agriculture. Signs of deficiency include muscle cramps, fatigue, insomnia, irritability, anxiety, depression, osteoporosis, and high blood pressure. Other factors that can deplete magnesium include stress, alcoholism, and the use of prescription drugs, such as diuretics, estrogen, and oral contraceptives.

Try for a daily intake of 1,000 mg of calcium and 500 mg of magnesium. Your body needs these minerals at a suggested ratio of 1:2. Check the ingredients list on your multivitamin label to determine that you are getting these levels. A calcium supplement may be needed to meet daily requirements.

Food Sources for These Minerals

Calcium is found in dairy products, tofu, leafy green vegetables, and canned fish with edible bones, such as sardines and salmon.

Magnesium is found in whole grains, nuts, seeds, legumes, green leafy vegetables, and tofu.

Vitamin D, Too

Take calcium and magnesium with vitamin D, which aids absorption and utilization by the bones. For most people, 400 IU of vitamin D is adequate.

Sherry Torkos, BSc Pharm, is a pharmacist and writer with training in both conventional and complementary medicine. sherrytorkos.com

Source: alive #285, July 2006

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