About magnesium

What is magnesium ?

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. 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 of 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. Magnesium is most commonly used for constipation, as an antacid for heartburn, for low magnesium levels, for pregnancy complications called pre-eclampsia and eclampsia, and for a certain type of irregular heartbeat (torsades de pointes). How does it work ? 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.

What are the uses & effectiveness ?

Effective for Bowel preparation. Taking magnesium by mouth is helpful for preparing the bowel for medical procedures. Constipation. Taking magnesium by mouth is helpful as a laxative for constipation. Indigestion (dyspepsia). Taking magnesium by mouth as an antacid reduces symptoms of heartburn and indigestion. Various magnesium compounds can be used, but magnesium hydroxide seems to work the fastest. Seizures in women with eclampsia. Administering magnesium intravenously (by IV) or as a shot is considered the treatment of choice for eclampsia. Administering magnesium reduces the risk of seizures in those with this condition. Low levels of magnesium in the blood (hypomagnesemia). Taking magnesium supplements can treat and prevent magnesium deficiency. Magnesium deficiency can occur when people have liver disorders, heart failure, vomiting or diarrhea, kidney dysfunction, and other conditions. A pregnancy complication marked by high blood pressure and protein in the urine (pre-eclampsia). Administering magnesium intravenously (by IV) or as a shot is considered the treatment of choice for preventing seizures in females with pre-eclampsia. But taking magnesium by mouth doesn't seem to reduce the risk for pre-eclampsia in healthy adults. Likely Effective for Cerebral palsy. The best evidence to date shows that giving intravenous (IV) magnesium to pregnant patients before a preterm birth can reduce the risk of cerebral palsy in the infant. Seizures. Giving magnesium intravenously (by IV) is helpful for treating various types of seizures. A type of irregular heartbeat (torsades de pointes). Giving magnesium intravenously (by IV) is helpful for treating a certain type of irregular heartbeat called torsades de pointes. Possibly Effective for Irregular heartbeat (arrhythmias). Giving magnesium intravenously (by IV) or by mouth seems to be helpful for treating irregular heartbeat, also called arrhythmias. It is not yet clear whether magnesium helps reduce irregular heartbeat after heart surgery. Asthma. Giving magnesium intravenously (by IV) seems to help treat sudden asthma attacks. It might be more beneficial in children than in adults. But inhaling magnesium or taking magnesium by mouth doesn't seem to work. Colon cancer, rectal cancer. Research shows that eating more foods with magnesium in them is linked to a reduced risk of colon and rectal cancer. But other research suggests that magnesium might reduce colon cancer risk, but not rectal cancer risk. Diabetes. Eating a diet with more magnesium is linked with a reduced risk of developing diabetes in adults and overweight children. Research in people existing type 2 diabetes is conflicting. However, magnesium supplements might be most helpful in people with type 2 diabetes and low magnesium levels. In people who developed diabetes during pregnancy, taking magnesium seems to improve sensitivity to insulin and reduce the levels of sugar in the blood. High cholesterol. Taking magnesium chloride and magnesium oxide appears to slightly decrease low-density lipoprotein (LDL or "bad") and total cholesterol levels, and slightly increase in high-density lipoprotein (HDL or "good") cholesterol levels in people with high cholesterol. There is also some evidence that magnesium might lower blood fats called triglycerides in people with high triglyceride levels. A grouping of symptoms that increase the risk of diabetes, heart disease, and stroke (metabolic syndrome). People with low magnesium levels are 6-7 times more likely to have metabolic syndrome than people with normal magnesium levels. Higher magnesium intake from diet and supplements is linked with a lower risk of developing metabolic syndrome in healthy adults. Weak and brittle bones (osteoporosis). Taking magnesium by mouth seems to prevent bone loss in older females with osteoporosis. Pain after surgery. When administered with anesthesia or given to people after surgery, magnesium seems to increase the amount of time before pain develops and might decrease the need to use pain relievers after surgery. Giving magnesium intravenously (by IV) seems to help reduce pain after a surgical procedure to remove the uterus called a hysterectomy. But magnesium does not seem to help reduce pain in children after tonsil removal. Premenstrual syndrome (PMS). Taking magnesium by mouth seems to relieve symptoms of PMS, including mood changes and bloating. Taking magnesium by mouth also seems to prevent premenstrual migraines. Chest pain due to blood vessel spasms (vasospastic angina). Giving magnesium intravenously (by IV) seems to prevent blood vessel spasms in people with chest pain caused by spasms in the artery that supplies blood to the heart. Possibly Ineffective for Altitude sickness. Taking magnesium citrate by mouth doesn't reduce the risk of altitude sickness. Athletic performance. Taking magnesium by mouth doesn't increase energy or endurance during athletic activity. Swelling (inflammation) of small airways in the lung (bronchiolitis). Giving magnesium by IV does not help and might even worsen bronchiolitis in infants. IV products can only be given by a healthcare provider. Nerve damage in the hands and feet caused by cancer drug treatment. Taking magnesium does not prevent nerve damage caused by the cancer drug oxaliplatin. Limb pain that usually occurs after an injury (complex regional pain syndrome). Taking magnesium by IV does not improve pain in people with chronic pain after an injury. IV products can only be given by a healthcare provider. Symptoms of menopause. Taking magnesium oxide by mouth doesn't reduce hot flashes. Muscle cramps. Taking magnesium supplements by mouth does not seem to decrease the frequency or intensity of muscle cramps. Injury to the brain, spine, or nerves (neurological trauma). Treatment with magnesium does not improve the outcome or reduce the risk of death for people with a traumatic head injury. It's not clear if taking magnesium by mouth is helpful in people with a concussion. Sickle cell disease. Giving magnesium sulfate by IV does not benefit children with sickle cell disease who are in the hospital. IV products can only be given by a healthcare provider. Stillbirth. Taking magnesium supplements by mouth during pregnancy does not seem to decrease the risk of a stillbirth. A serious infection caused by Clostridium bacteria (tetanus). Taking magnesium by IV does not seem to reduce the risk of death in people with tetanus. IV products can only be given by a healthcare provider. There is interest in using magnesium for a number of other purposes, but there isn't enough reliable information to say whether it might be helpful. Insufficient Evidence for Alcohol use disorder. Taking magnesium by mouth seems to improve sleep quality in people who are dependent on alcohol and going through withdrawal. However, injecting magnesium as a shot does not seem to reduce alcohol withdrawal symptoms. Attention deficit-hyperactivity disorder (ADHD). Children with ADHD seem to have lower magnesium levels. Early research suggests that magnesium might be helpful for children with ADHD who have low magnesium levels. Back pain. Early research suggests that receiving magnesium intravenously (by IV) every 4 hours for 2 weeks while taking magnesium by mouth daily for 4 weeks reduces pain in people with chronic low back pain. Bipolar disorder. Early research suggests that taking a certain magnesium product (Magnesiocard) may have similar effects as lithium in some people with bipolar disorder. Other early research suggests that taking magnesium by mouth along with the drug verapamil reduces manic symptoms better than verapamil alone in people with bipolar disorder. Also, giving magnesium intravenously (by IV) seems to reduce the dose of other drugs needed to manage severe manic symptoms. Nerve pain in people with cancer. Giving magnesium intravenously (by IV) seems to help relieve pain caused by nerve damage due to cancer. Damage to the immune system caused by cancer drug treatment. Early research shows that taking magnesium by mouth might prevent immune system damage in children receiving the cancer drug cisplatin. Sudden loss of heart function (cardiac arrest). Some preliminary research suggests that higher levels of magnesium are linked with a lower chance of cardiac arrest. However, it is not known if taking a magnesium supplement reduces the risk of cardiac arrest. Giving magnesium intravenously does not seem to have a benefit. Heart disease (cardiovascular disease). It is unclear if people who get more magnesium as part of their diet have a lower chance of heart disease. Some research has found that increasing magnesium intake in the diet is linked to a reduced risk of death related to heart disease. But other research has found no benefit. Chronic fatigue syndrome (CFS). Administering magnesium as a shot might improve symptoms of fatigue. But not all research agrees. A lung disease that makes it harder to breathe (chronic obstructive pulmonary disease or COPD). Administering magnesium intravenously (by IV) seems to help sudden COPD symptoms. Also, taking magnesium using an inhaler, along with the drug salbutamol, seems to reduce sudden COPD symptoms better than salbutamol alone. Cluster headache. Early research shows that giving magnesium intravenously (by IV) might relieve cluster headaches. Heart disease (coronary heart disease). Early research shows that taking magnesium by mouth might reduce blood clots in people with heart disease. Depression. It is unclear if people who get more magnesium as part of their diet have a lower chance of depression. It is also too early to know if magnesium can reduce symptoms in people with depression. Taking magnesium by mouth for 6 weeks seems to reduce mild to moderate depression in adults. But getting a single dose of magnesium intravenously (by IV) doesn't reduce depression symptoms when measured one week later. Confusion and agitation after surgery. Early research suggests that IV magnesium does not reduce confusion and agitation in children after surgery. Muscle soreness caused by exercise. Early research suggests that taking magnesium for 10 days might reduce muscle soreness after lifting weights. Fibromyalgia. Early research shows that taking magnesium citrate daily for 8 weeks might improve some symptoms of fibromyalgia. Fractures. People who get more magnesium from their diet or as supplements seem to have a lower risk of fractures. Stomach cancer. People who get more magnesium from their diet or as supplements do not seem to have a lower risk of stomach cancer. Hearing loss. Taking magnesium by mouth seems to prevent hearing loss in people exposed to loud noise. Also, taking magnesium seems to improve hearing loss in people with sudden hearing loss that is not from loud noise. High blood pressure. Most research shows that taking magnesium can lower diastolic blood pressure (the bottom number in a blood pressure reading) by about 2 mmHg. This decrease might be too small to have a meaningful impact on high blood pressure. There's conflicting data about the effects of magnesium on systolic blood pressure (the top number in a blood pressure reading). Insomnia. Magnesium might reduce insomnia in the elderly. But it doesn't seem to improve sleep in people without insomnia. Bleeding into or around the fluid-filled areas (ventricles) of the brain (intraventricular hemorrhage). Early research suggests that premature infants might have a lower risk of a brain bleed if their mothers receive magnesium by IV while pregnant. Kidney stones. Some research shows that taking magnesium by mouth might prevent kidney stones in people who have had kidney stones. Liver cancer. People who get more magnesium from their diet seem to have a lower risk of liver cancer. Migraine. Taking high doses of magnesium by mouth might help prevent migraines and make them a little less severe. But not all research agrees. IV magnesium might relieve migraines in people that don't get enough magnesium in their diet. Heart attack. In general, giving magnesium intravenously (by IV) or taking magnesium by mouth does not seem to reduce the overall risk of death after a heart attack. Brain damage in infants caused by lack of oxygen. Research suggests that administering magnesium intravenously (by IV) might improve outcomes in infants with brain damage caused by lack of oxygen in the short-term. But it doesn't seem to have long-term benefit. Obesity. It is unclear if taking magnesium by mouth improves weight loss in obese people. If it does, any benefits are likely to be small. Death from any cause. Consuming more magnesium in the diet is linked to a lower risk of death. However, taking magnesium supplements does not seem to reduce this risk. Pain (chronic). People who get more magnesium from their diet or supplements seem to have a slightly lower risk of chronic pain. Physical performance in elderly adults. Some research shows that taking magnesium daily for 12 weeks might help elderly females to walk further. A hormonal disorder that causes enlarged ovaries with cysts (polycystic ovary syndrome or PCOS). Taking magnesium does not seem to reduce insulin resistance in PCOS. Leg cramps in women who are pregnant. Most research shows that taking magnesium by mouth might reduce leg cramps during pregnancy. But not all research agrees. Preterm birth. Giving magnesium intravenously (by IV) might prevent contractions when premature labor occurs. Some research suggests that magnesium is more effective at delaying labor by 48 hours compared to some conventional drugs. But not all experts believe it is beneficial, and some research suggests it might cause more adverse effects. A rare, inherited disorder that causes buildup of minerals in the skin, eyes, and blood vessels (Pseudoxanthoma elasticum or PXE). Early research suggests that magnesium supplementation might reduce buildup of minerals in people with PXE. A disorder that causes leg discomfort and an irresistible urge to move the legs (restless legs syndrome or RLS). Taking magnesium by mouth might decrease the amount of movement and increase the amount of sleep in patients with restless legs syndrome. However, the role of magnesium, if any, in restless legs syndrome is uncertain. Some people with this condition have high levels of magnesium in their blood, while others have low magnesium levels. Stroke. Most early research found that increased intake of magnesium in the diet is linked with a reduced risk of death from stroke. There is also some evidence that increased dietary intake of magnesium seems to improve mental ability in people after stroke. But the effects of intravenous (IV) magnesium are mixed. Some research shows that it might protect the brain after stroke. But other research shows that it does not reduce the risk of death or disability in most people. Bleeding in the space surrounding the brain (subarachnoid hemorrhage). There is mixed evidence about the effect of magnesium in managing bleeding in the brain. Some research suggests that giving magnesium intravenously (by IV) reduces the risk of death and vegetative state. However, other research does not support these findings. Allergic rhinitis. Hay fever. Urinary incontinence. Other conditions. More evidence is needed to rate magnesium for these uses.

What are the side effects?

What are the precautions and warnings?

Magnesium is LIKELY SAFE for most people when taken appropriately. Doses less than 350 mg daily are safe for most adults. In some people, magnesium might cause stomach upset, nausea, vomiting, diarrhea, and other side effects. When taken in very large amounts (greater than 350 mg daily), 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. When given as a shot or by IV: Magnesium is LIKELY SAFE for most people when the prescription-only, injectable product is used correctly by a healthcare provider. Pregnancy and breast-feeding: Magnesium is LIKELY SAFE for those pregnant or breast-feeding when taken by mouth in doses less than 350 mg daily. Magnesium is POSSIBLY SAFE when the prescription-only, injectable product is given by IV or as a shot for up to 5 days before delivery. But prescription-only magnesium is given during pregnancy only for serious health conditions. There is evidence that using magnesium to suppress early labor might cause serious problems in the infant. Magnesium is POSSIBLY UNSAFE when taken by mouth in high doses or when the prescription-only, injectable product is given by IV or as a shot for longer than 5 days. Taking magnesium by mouth in high doses can cause diarrhea and too much magnesium in the blood. Receiving prescription-only magnesium by IV or as a shot for longer than 5 days might cause bone and brain problems in the infant. Children: Magnesium is LIKELY SAFE for most children when taken by mouth appropriately or when the prescription-only, injectable product is used correctly. Magnesium is safe when taken by mouth 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 by mouth 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. Heart block: High doses of magnesium (typically delivered by IV) should not be given to people with heart block. A condition called myasthenia gravis: Magnesium given intravenously (by IV) might worsen weakness and cause breathing difficulties in people with a condition called myasthenia gravis. 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.

What are the interactions?

Major InteractionDo not take this combination Levodopa/Carbidopa (Sinemet) interacts with MAGNESIUM Levodopa/carbidopa (Sinemet) is used for Parkinson disease. Taking magnesium oxide along with levodopa/carbidopa might decrease the effectiveness of levodopa/carbidopa. Do not take magnesium oxide if you are taking levodopa/carbidopa.Moderate InteractionBe cautious with this combination Antibiotics (Aminoglycoside antibiotics) interacts with MAGNESIUM 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. Antibiotics (Quinolone antibiotics) interacts with MAGNESIUM 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), gemifloxacin (Factive), levofloxacin (Levaquin), moxifloxacin (Avelox), and others. Antibiotics (Tetracycline antibiotics) interacts with MAGNESIUM 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 tetracyclines include demeclocycline (Declomycin), minocycline (Minocin), and tetracycline (Achromycin). Bisphosphonates interacts with MAGNESIUM 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. Medications for high blood pressure (Calcium channel blockers) interacts with MAGNESIUM Some medications for high blood pressure work by blocking calcium from entering cells. These medications are called calcium channel blockers. Magnesium might also block calcium from entering cells. Taking magnesium with these medications might cause blood pressure to go too low.

Some of these medications include nifedipine (Adalat, Procardia), verapamil (Calan, Isoptin, Verelan), diltiazem (Cardizem), isradipine (DynaCirc), felodipine (Plendil), amlodipine (Norvasc), and others. Muscle relaxants interacts with MAGNESIUM Magnesium seems to help relax muscles. Taking magnesium along with muscle relaxants can increase the risk of side effects of muscle relaxants.

Some muscle relaxants include carisoprodol (Soma), pipecuronium (Arduan), orphenadrine (Banflex, Disipal), cyclobenzaprine, gallamine (Flaxedil), atracurium (Tracrium), pancuronium (Pavulon), succinylcholine (Anectine), and others. Water pills (Potassium-sparing diuretics) interacts with MAGNESIUM Some "water pills" can increase magnesium levels in the body. Taking some "water pills" along with magnesium might cause too much magnesium to be in the body.

Some "water pills" that increase magnesium in the body include amiloride (Midamor), spironolactone (Aldactone), and triamterene (Dyrenium). Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs) interacts with MAGNESIUM Magnesium might slow blood clotting. Taking magnesium along with medications that also slow clotting might increase the chances of bruising and bleeding.

Some medications that slow blood clotting include aspirin, clopidogrel (Plavix), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, indomethacin (Indocin), ticlopidine (Ticlid), warfarin (Coumadin), and others. Digoxin (Lanoxin) interacts with MAGNESIUM 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). Medications for diabetes (Sulfonylureas) interacts with MAGNESIUM Magnesium is available in supplements in several salt forms. Some salt forms of magnesium might increase how much sulfonylurea the body absorbs. By increasing how much sulfonylurea the body absorbs, these forms of magnesium might increase the risk of low blood sugar in some patients.

Some sulfonylurea agents include carbutamide, acetohexamide, chlorpropamide, tolbutamide, gliclazide, glibornuride, glyclopyramide, and glimepiride. Antacids interacts with MAGNESIUM 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. Gabapentin (Neurontin) interacts with MAGNESIUM 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. Ketamine (Ketalar) interacts with MAGNESIUM Ketamine is used for severe pain and depression. Taking large doses of magnesium along with ketamine might increase the effects and side effects of ketamine.Minor InteractionBe watchful with this combination Sevelamer (Renagel, Renvela) interacts with MAGNESIUM Sevelamer (Renagel, Renvela) can increase magnesium levels in the body. Taking sevelamer with a magnesium supplement might cause magnesium levels to get too high.

Talk to your healthcare provider before taking magnesium supplements if you are taking sevelamer.

What is the dosing?

The following doses have been studied in scientific research: ADULTS BY MOUTH: General: The daily Recommended Dietary Allowances (RDA) for elemental magnesium are: 19-30 years, 400 mg (men) and 310 mg (women); 31 years and older, 420 mg (men) and 320 mg (women). For pregnancy: age 14-18 years, the RDA is 400 mg; 19-30 years, 350 mg; 31-50 years, 360 mg. For lactation: age 14-18 years, the RDA is 360 mg; 19-30 years, 310 mg; 31-50 years, 320 mg. The daily upper intake level (UL) for magnesium is 350 mg for anyone over 8 years old, including those that are pregnant and breast-feeding. For constipation: 8.75-25 grams of magnesium citrate has been used, usually as 150-300 mL in a 290 mg/ 5 mL solution. 2.4-4.8 grams of magnesium hydroxide has also been used. 10-30 grams of magnesium sulfate has also been used. Magnesium salts should only be used for occasional treatment of constipation, and doses should be taken with a full 8 oz glass of water. For indigestion (dyspepsia): 400-1200 mg of magnesium hydroxide has been used up to four times daily. 800 mg of magnesium oxide daily has also been used. For low levels of magnesium in the blood (hypomagnesemia): 3 grams of magnesium sulfate, taken every 6 hours for four doses, has been used. A 5% solution of magnesium chloride has been used by mouth daily for 16 weeks. Magnesium-rich mineral water (Hepar) containing 110 mg/L has also been used. 10.4 mmol of magnesium lactate, taken by mouth daily for 3 months, has been used. Avoid magnesium oxide and magnesium carbonate. For irregular heartbeat (arrhythmias): 2.163 mg of magnesium-DL-hydrogen aspartate and 2.162 mg of potassium-DL-hydrogen aspartate given daily for 21 days has been used. For diabetes: For type 2 diabetes, 2.5 grams of magnesium chloride in a 50 mL solution daily for 16 weeks has been used. 300 mL of salt lake water with naturally high magnesium content diluted with distilled water to contain 100 mg of magnesium per 100 mL of water has been used daily for 30 days. 360 mg of magnesium daily for 4 to 16 weeks has been used. For type 1 diabetes, 300 mg of a specific magnesium gluconate supplement (Ultramagnesium) daily for 5 years has been used. For high cholesterol: 1 gram of magnesium oxide daily for 6 weeks has been used. For a grouping of symptoms that increase the risk of diabetes, heart disease, and stroke (metabolic syndrome): 365 mg of magnesium aspartate daily for 6 months has been used. For weak and brittle bones (osteoporosis): 300-1800 mg of magnesium hydroxide taken daily for 6 months, followed by 600 mg of magnesium hydroxide taken daily for 18 months, has been used. 1830 mg of magnesium citrate has been used daily for 30 days. In addition to estrogen, 600 mg of magnesium plus 500 mg of calcium and a multivitamin supplement has been used daily for one year. For premenstrual syndrome (PMS): 333 mg of magnesium oxide taken daily for two menstrual cycles has been used. A higher dose of 360 mg elemental magnesium three times daily has been used from the 15th day of the menstrual cycle until menstrual period begins. 360 mg of elemental magnesium taken three times daily for 2 months has been used. A combination of 200 mg of magnesium daily plus 50 mg of vitamin B6 daily has been used. BY IV: For seizures in women with pre-eclampsia: 4-5 grams of magnesium sulfate by IV infusion, followed by 4-5 grams of magnesium sulfate every 4 hours, or 1 to 3 grams of magnesium sulfate per hour by constant IV infusion has been used. Doses should not exceed 30 to 40 grams of magnesium sulfate daily. A higher dose of magnesium sulfate (9-14 grams) followed by a smaller dose (2.5-5 grams every 4 hours for 24 hours) has also been used. For low levels of magnesium in the blood (hypomagnesemia): A typical starting dose for mild deficiency is 1 gram of magnesium sulfate intramuscularly (IM) every 6 hours for 4 doses. For more severe deficiency, 5 grams of magnesium sulfate may be given as an intravenous (IV) infusion over 3 hours. To prevent magnesium deficiency, adults typically receive 60-96 mg of elemental magnesium daily. For a pregnancy complication marked by high blood pressure and protein in the urine (pre-eclampsia): 4-5 grams of magnesium sulfate by IV infusion, followed by 4-5 grams of magnesium sulfate every 4 hours, or 1 to 3 grams of magnesium sulfate per hour by constant IV infusion has been used. Doses should not exceed 30 to 40 grams of magnesium sulfate daily. A higher dose of magnesium sulfate (9grams) followed by a smaller dose (5 grams every 4 hours for 24 hours) has also been used. For a type of irregular heartbeat (torsades de pointes): 1 to 6 grams of magnesium sulfate given by IV over several minutes, followed by an IV infusion has been used. For irregular heartbeat (arrhythmias): For reducing irregular heartbeat after a heart attack, 8 grams of magnesium sulfate in 250 mL of solution over 12 hours has been used. For irregular or rapid heartbeat, an IV infusion of 5 grams of magnesium sulfate in 100 mL of solution has been used. Half of the dose is given over 20 minutes, followed by the remainder over 2 hours. For faster heartbeat, a single IV dose of 1-4 grams of magnesium chloride given over 5 minutes has been used. For abnormal heartbeat caused by a pacemaker, 2 grams of magnesium sulfate in 10 mL of solution has been given by IV over 1-10 minutes, followed by 5-10 grams of magnesium sulfate in 250-500 mL of solution over 5 hours. For asthma: Doses of 1-2 grams of magnesium sulfate have been given over 20 to 30 minutes. A dose of 78 mg/kg/hour of magnesium sulfate has been given by IV during, and for 30 minutes before, a lung function test. For nerve pain in people with cancer: Single doses of 0.5-1 gram of magnesium sulfate have been given as 1 mL or 2 mL of a 50% magnesium sulfate injection over 5-10 minutes. For cerebral palsy: For preventing cerebral palsy in the infant, 4 grams of magnesium sulfate has been given by IV over 10-30 minutes to females close to their expected due date. Magnesium sulfate is then sometimes given by IV at a dose of 1 gram per hour until birth or for 24 hours has been used. For pain after surgery: 5-50 mg/kg of magnesium by IV followed by a continuous IV solution at 6 mg/kg or 500 mg hourly has been used for the duration of the operation up to 48 hours. Also, 3.7-5.5 grams of magnesium in addition to pain medication has been used within 24 hours after surgery. In addition, 3 grams of magnesium sulfate in an IV solution has been used followed by 0.5 grams of magnesium sulfate by IV per hour for 20 hours. For chest pain due to blood vessel spasms (vasospastic angina): 65 mg/kg of body weight of magnesium given by IV over 20 minutes has been used. INJECTED AS A SHOT: For seizures in women with pre-eclampsia: 4-5 grams of magnesium sulfate diluted in saline over 10-15 minutes given intravenously (by IV) followed by 5 grams of magnesium sulfate injected as a shot into each buttock, and 2.5 or 5 grams of magnesium sulfate injected as a shot every 4 hours for 24 hours has been used. For a pregnancy complication marked by high blood pressure and protein in the urine (pre-eclampsia): 4-5 grams of magnesium sulfate diluted in saline over 10-15 minutes given intravenously (by IV) followed by 5 grams of magnesium sulfate injected as a shot into each buttock, and 5 grams of magnesium sulfate injected as a shot every 4 hours for 24 hours has been used. CHILDREN BY MOUTH: General: The daily Recommended Dietary Allowances (RDA) for elemental magnesium are: Age 1-3 years, 80 mg; 4-8 years, 130 mg; 9-13 years, 240 mg; 14-18 years, 410 mg (boys) and 360 mg (girls). For infants less than one year of age, adequate intake (AI) levels are 30 mg from birth to 6 months and 75 mg from 7 to 12 months. The daily upper intake level (UL) for magnesium is 65 mg for children age 1-3 years, and 110 mg for 4-8 years. BY IV: For asthma: 40 mg/kg of magnesium sulfate, up to a maximum of 2 grams, has been given by IV in 100 mL of solution over 20 minutes.