Magnesium is a mineral that is present in relatively large amounts in the body. Researchers estimate that the average person's body contains about 25 grams of magnesium, and about half of that is in the bones. Magnesium is important in more than 300 chemical reactions that keep the body working properly. Magnesium is required for the proper growth and maintenance of bones. Magnesium is also required for the proper function of nerves, muscles, and many other parts of the body. In the stomach, magnesium helps neutralize stomach acid and moves stools through the intestine. People get magnesium from their diet, but sometimes magnesium supplements are needed if magnesium levels are too low. Dietary intake of magnesium may be low, particularly among women. An easy way to remember foods that are good magnesium sources is to think fiber. Foods that are high in fiber are generally high in magnesium. Dietary sources of magnesium include legumes, whole grains, vegetables (especially broccoli, squash, and green leafy vegetables), seeds, and nuts (especially almonds). Other sources include dairy products, meats, chocolate, and coffee. Water with a high mineral content, or "hard" water, is also a source of magnesium.

People take magnesium to prevent or treat magnesium deficiency. Magnesium is also used as a laxative for constipation and for preparation of the bowel for surgical or diagnostic procedures. It is also used as an antacid for acid indigestion. Some people use magnesium for diseases of the heart and blood vessels including chest pain, irregular heartbeat, high blood pressure, high levels of "bad" cholesterol called low-density lipoprotein (LDL) cholesterol, low levels of "good" cholesterol called high-density lipoprotein (HDL) cholesterol, heart valve disease (mitral valve prolapse), and heart attack.

Magnesium is also used for treating attention deficit-hyperactivity disorder (ADHD), anxiety, chronic fatigue syndrome (CFS), Lyme disease, fibromyalgia, leg cramps during pregnancy, diabetes, kidney stones, migraine headaches, weak bones (osteoporosis), premenstrual syndrome (PMS), altitude sickness, urinary incontinence, restless leg syndrome, asthma, hay fever, multiple sclerosis, and for preventing hearing loss. Athletes sometimes use magnesium to increase energy and endurance.

Some people put magnesium on their skin to treat infected skin ulcers, boils, and carbuncles; and to speed up wound healing. Magnesium is also used as a cold compress in the treatment of a severe skin infection caused by strep bacteria (erysipelas) and as a hot compress for deep-seated skin infections.

What is Magnesium?
Magnesium is the fourth most abundant mineral in the body and is essential to good health. Approximately 50% of total body magnesium is found in bone. The other half is found predominantly inside cells of body tissues and organs. Only 1% of magnesium is found in blood, but the body works very hard to keep blood levels of magnesium constant.

Magnesium is needed for more than 300 biochemical reactions in the body. It helps maintain normal muscle and nerve function, keeps heart rhythm steady, supports a healthy immune system, and keeps bones strong. Magnesium also helps regulate blood sugar levels, promotes normal blood pressure, and is known to be involved in energy metabolism and protein synthesis .There is an increased interest in the role of magnesium in preventing and managing disorders such as hypertension, cardiovascular disease, and diabetes. Dietary magnesium is absorbed in the small intestines. Magnesium is excreted through the kidneys.

Where it is found
Green vegetables such as spinach are good sources of magnesium because the center of the chlorophyll molecule (which gives green vegetables their color) contains magnesium. Some legumes (beans and peas), nuts and seeds, and whole, unrefined grains are also good sources of magnesium . Refined grains are generally low in magnesium. When white flour is refined and processed, the magnesium-rich germ and bran are removed. Bread made from whole grain wheat flour provides more magnesium than bread made from white refined flour. Tap water can be a source of magnesium, but the amount varies according to the water supply. Water that naturally contains more minerals is described as "hard". "Hard" water contains more magnesium than "soft" water.

Benefits / uses
Magnesium and blood pressure
"Epidemiologic evidence suggests that magnesium may play an important role in regulating blood pressure." Diets that provide plenty of fruits and vegetables, which are good sources of potassium and magnesium, are consistently associated with lower blood pressure. The DASH study (Dietary Approaches to Stop Hypertension), a human clinical trial, suggested that high blood pressure could be significantly lowered by a diet that emphasizes fruits, vegetables, and low fat dairy foods. Such a diet will be high in magnesium, potassium, and calcium, and low in sodium and fat.
An observational study examined the effect of various nutritional factors on incidence of high blood pressure in over 30,000 US male health professionals. After four years of follow-up, it was found that a lower risk of hypertension was associated with dietary patterns that provided more magnesium, potassium, and dietary fiber. For 6 years, the Atherosclerosis Risk in Communities (ARIC) Study followed approximately 8,000 men and women who were initially free of hypertension. In this study, the risk of developing hypertension decreased as dietary magnesium intake increased in women, but not in men.

Magnesium and diabetes
Magnesium plays an important role in carbohydrate metabolism. It may influence the release and activity of insulin, the hormone that helps control blood glucose (sugar) levels. Low blood levels of magnesium (hypomagnesemia) are frequently seen in individuals with type 2 diabetes. Hypomagnesemia may worsen insulin resistance, a condition that often precedes diabetes, or may be a consequence of insulin resistance. Individuals with insulin resistance do not use insulin efficiently and require greater amounts of insulin to maintain blood sugar within normal levels. The kidneys possibly lose their ability to retain magnesium during periods of severe hyperglycemia (significantly elevated blood glucose). The increased loss of magnesium in urine may then result in lower blood levels of magnesium. In older adults, correcting magnesium depletion may improve insulin response and action.
Several clinical studies have examined the potential benefit of supplemental magnesium on control of type 2 diabetes. In one such study, 63 subjects with below normal serum magnesium levels received either 2.5 grams of oral magnesium chloride daily "in liquid form" (providing 300 mg elemental magnesium per day) or a placebo. At the end of the 16-week study period, those who received the magnesium supplement had higher blood levels of magnesium and improved control of diabetes, as suggested by lower hemoglobin A1C levels, than those who received a placebo. Hemoglobin A1C is a test that measures overall control of blood glucose over the previous 2 to 3 months, and is considered by many doctors to be the single most important blood test for diabetics.
In 1999, the American Diabetes Association (ADA) issued nutrition recommendations for diabetics stating that "routine evaluation of blood magnesium level is recommended only in patients at high risk for magnesium deficiency"
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Magnesium and cardiovascular disease
Magnesium metabolism is very important to insulin sensitivity and blood pressure regulation, and magnesium deficiency is common in individuals with diabetes. The observed associations between magnesium metabolism, diabetes, and high blood pressure increase the likelihood that magnesium metabolism may influence cardiovascular disease.

Some observational surveys have associated higher blood levels of magnesium with lower risk of coronary heart disease. In addition, some dietary surveys have suggested that a higher magnesium intake may reduce the risk of having a stroke. There is also evidence that low body stores of magnesium increase the risk of abnormal heart rhythms, which may increase the risk of complications after a heart attack. These studies suggest that consuming recommended amounts of magnesium may be beneficial to the cardiovascular system. They have also prompted interest in clinical trials to determine the effect of magnesium supplements on cardiovascular disease.

Several small studies suggest that magnesium supplementation may improve clinical outcomes in individuals with coronary disease. In one of these studies, the effect of magnesium supplementation on exercise tolerance (the ability to walk on a treadmill or ride a bicycle), chest pain caused by exercise, and quality of life was examined in 187 patients. Patients received either a placebo or a supplement providing 365 milligrams of magnesium citrate twice daily for 6 months. At the end of the study period researchers found that magnesium therapy significantly increased magnesium levels. Patients receiving magnesium had a 14 percent improvement in exercise duration as compared to no change in the placebo group. Those receiving magnesium were also less likely to experience chest pain caused by exercise.

In a study, researchers examined whether magnesium supplementation would add to the anti-thrombotic (anti-clotting) effects of aspirin in 42 coronary patients. For three months, each patient received either a placebo or a supplement with 400 mg of magnesium oxide two to three times daily. After a four-week break without any treatment, treatment groups were reversed so that each person in the study then received the alternate treatment for three months. Researchers found that supplemental magnesium did provide an additional anti-thrombotic effect.

Magnesium and osteoporosis
Bone health is supported by many factors, most notably calcium and vitamin D. However, some evidence suggests that magnesium deficiency may be an additional risk factor for postmenopausal osteoporosis. This may be due to the fact that magnesium deficiency alters calcium metabolism and the hormones that regulate calcium. Several human studies have suggested that magnesium supplementation may improve bone mineral density. In a study of older adults, a greater magnesium intake maintained bone mineral density to a greater degree than a lower magnesium intake. Diets that provide recommended levels of magnesium are beneficial for bone health.

When to take/ Types to take
Magnesium supplements are best taken with a meal and together with calcium if the goal is building strong, healthy bones.
Supplement magnesium is available in many forms. These include an amino acid chelate, citrate, aspartate, ascorbate, lactate, lysinate, picolinate, gluconate, chloride, sulfate and oxide. Any of these forms (or a mix of them) will provide a good source of magnesium.

Doses
Recommended Dietary Allowances for magnesium for children and adults

Possible Side effects / Precautions / Possible Interactions:
Magnesium is safe for most people when taken by mouth or when the prescription-only, injectable product is used correctly. In some people, magnesium might cause stomach upset, nausea, vomiting, diarrhea, and other side effects.

Doses less than 450 mg per day are safe for most adults. When taken in very large amounts, magnesium is possibly unsafe and may cause diarrhea.

Special Precautions & Warnings:
Pregnancy and breast-feeding: Magnesium is likely safe for pregnant or breast-feeding women when taken by mouth in the amounts recommended. These amounts depend on the age of the woman.

Heart block: High doses of magnesium (typically delivered by IV) should not be given to people with heart block.

Kidney problems, such as kidney failure: Kidneys that don't work well have trouble clearing magnesium from the body. Taking extra magnesium can cause magnesium to build up to dangerous levels. Don't take magnesium if you have kidney problems.

Research studies / References