Magnesium is a mineral that is important for normal bone structure in the body. 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. Magnesium deficiency is also not uncommon among African Americans and the elderly. Low magnesium levels in the body have been linked to diseases such as osteoporosis, high blood pressure, clogged arteries, hereditary heart disease, diabetes, and stroke.
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 by mouth to prevent magnesium deficiency. It 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), metabolic syndrome, clogged arteries (coronary artery disease), stroke, and heart attack.
Magnesium is also used for treating attention deficit-hyperactivity disorder (ADHD), anxiety, chronic fatigue syndrome (CFS), Lyme disease, fibromyalgia, cystic fibrosis, alcoholism, mania, recovery after surgery, leg cramps at night and during pregnancy, diabetes, kidney stones, migraine headaches, a long-term pain condition called complex regional pain syndrome, weak bones (osteoporosis), premenstrual syndrome (PMS), altitude sickness, urinary incontinence, a condition that causes burning pain and redness called erythromelalgia, a disorder that causes a strong urge to move ones legs (restless legs syndrome; RLS), asthma, hayfever, multiple sclerosis, and for preventing hearing loss and cancer.
Athletes sometimes use magnesium to increase energy and endurance.
Some people apply 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.
Magnesium is injected into the body for nutritional purposes and to treat magnesium deficiency that occurs in people with pancreas infections, magnesium absorption disorders, and cirrhosis. It is also injected to treat high blood pressure during pregnancy and other pregnancy complications.
Magnesium is also used as an injection to control seizures, to treat irregular heartbeat, to control irregular heartbeat after a heart attack, and for cardiac arrest. Magnesium is also injected into the body to treat asthma and other lung disease complications, for migraines and cluster headaches, jellyfish stings, poisonings, pain, swelling in the brain, chemotherapy side effects, head trauma and bleeding, sickle cell disease, to prevent cerebral palsy, and for tetanus.
How it works
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.
Taking magnesium by mouth is helpful as a laxative for constipation and to prepare the bowel for medical procedures.
Taking magnesium by mouth as an antacid reduces symptoms of heartburn. Various magnesium compounds can be used, but magnesium hydroxide seems to work the fastest.
Taking magnesium is helpful for treating and preventing magnesium deficiency. Magnesium deficiency usually occurs when people have liver disorders, heart failure, vomiting or diarrhea, kidney dysfunction, and other conditions.
Administering magnesium intravenously (by IV) or as a shot is considered the treatment of choice for reducing high blood pressure during pregnancy (pre-eclampsia) and for treating eclampsia, which includes the development of seizures. Research suggests that administering magnesium reduces the risk of seizures.
Magnesium is LIKELY SAFE for most people when taken by mouth appropriately 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 350 mg daily are safe for most adults
When taken in very large amounts, magnesium is POSSIBLY UNSAFE. Large doses might cause too much magnesium to build up in the body, causing serious side effects including an irregular heartbeat, low blood pressure, confusion, slowed breathing, coma, and death.
Pregnancy and breast-feeding: Magnesium isLIKELY SAFEfor pregnant orbreast-feeding women when taken in doses less than 350 mg daily. Magnesium isPOSSIBLY SAFEwhen injected as a shot or intravenously (by IV) before delivery. Magnesium isPOSSIBLY UNSAFEwhen taken by mouth or by IV in high doses.
Children: Magnesium is LIKELY SAFE for most people when taken by mouth appropriately or when the prescription-only, injectable product is used correctly. Magnesium is safe when taken in doses less than 65 mg for children 1-3 years, 110 mg for children 4-8 years, and 350 mg for children older than 8 years. Magnesium is LIKELY UNSAFE when taken in higher doses.
Alcoholism: Alcohol abuse increases the risk for magnesium deficiency.
Bleeding disorders: Magnesium seem to slow blood clotting. In theory, taking magnesium might increase the risk of bleeding or bruising in people with bleeding disorders.
Diabetes: Diabetes increases the risk for magnesium deficiency. Poorly controlled diabetes reduces how much magnesium the body absorbs.
Elderly: The elderly are at risk for magnesium deficiency due to reduced magnesium absorption by the body and often the presence of diseases that also affect magnesium absorption.
Heart block: High doses of magnesium (typically delivered by IV) should not be given to people with heart block.
Diseases that affect magnesium absorption: How much magnesium the body absorbs can be reduces by many conditions, including stomach infections, immune diseases, inflammatory bowel disease and others.
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.
A disorder that causes a strong urge to move ones legs (restless legs syndrome; RLS): People with restless legs syndrome might have high magnesium levels. But it's not clear if magnesium is the cause for this condition, as people with restless legs syndrome have also had magnesium deficiency.
Antacids might reduce the laxative effects of magnesium. People taking magnesium as a laxative might require a higher dose.Some antacids include calcium carbonate (Tums, others), dihydroxyaluminum sodium carbonate (Rolaids, others), magaldrate (Riopan), magnesium sulfate (Bilagog), aluminum hydroxide (Amphojel), and others.Some antibiotics can affect the muscles. These antibiotics are called aminoglycosides. Magnesium can also affect the muscles. Taking these antibiotics and getting a magnesium shot might cause muscle problems.Some aminoglycoside antibiotics include amikacin (Amikin), gentamicin (Garamycin), kanamycin (Kantrex), streptomycin, tobramycin (Nebcin), and others.Magnesium might decrease how much antibiotic the body absorbs. Taking magnesium along with some antibiotics might decrease the effectiveness of some antibiotics. To avoid this interaction, take these antibiotics at least 2 hours before, or 4 to 6 hours after, magnesium supplements.Some of these antibiotics that might interact with magnesium include ciprofloxacin (Cipro), enoxacin (Penetrex), norfloxacin (Chibroxin, Noroxin), sparfloxacin (Zagam), trovafloxacin (Trovan), and grepafloxacin (Raxar).Magnesium can attach to tetracyclines in the stomach. This decreases the amount of tetracyclines that the body can absorb. Taking magnesium along with tetracyclines might decrease the effectiveness of tetracyclines. To avoid this interaction, take calcium 2 hours before, or 4 hours after, taking tetracyclines.Some tetracyclines include demeclocycline (Declomycin), minocycline (Minocin), and tetracycline (Achromycin).Magnesium can decrease how much bisphosphate the body absorbs. Taking magnesium along with bisphosphates can decrease the effectiveness of bisphosphate. To avoid this interaction, take bisphosphonate at least two hours before magnesium or later in the day.Some bisphosphonates include alendronate (Fosamax), etidronate (Didronel), risedronate (Actonel), tiludronate (Skelid), and others.Digoxin (Lanoxin) helps the heart beat more strongly. Magnesium might decrease how much digoxin (Lanoxin) the body absorbs. By decreasing how much digoxin (Lanoxin) the body absorbs, magnesium might decrease the effects of digoxin (Lanoxin).Gabapentin (Neurontin)
Magnesium might decrease how much gabapentin (Neurontin) the body absorbs. By decreasing how much gabapentin (Neurontin) the body absorbs, magnesium might decrease the effects of gabapentin (Neurontin). Take gabapentin (Neurontin) at least 2 hours before, or 4 to 6 hours after taking magnesium supplements.