MAGNESIUM Overview Information
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, restless leg syndrome, 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 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.
- Constipation. Taking magnesium by mouth is helpful as a laxative for constipation and to prepare the bowel for medical procedures.
- Indigestion. 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.
- Magnesium deficiency. 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.
- High blood pressure during pregnancy (pre-eclampsia and eclampsia). 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.
Likely Effective for:
- 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 a certain type of irregular heartbeat called arrhythmias.
- Asthma. Giving magnesium intravenously (by IV) seems to help treat sudden asthma attacks. However, it might be more beneficial in children than in adults. Taking magnesium using an inhaler might improve breathing in people with asthma, especially when used with the drug salbutamol. But conflicting results exist. Taking magnesium by mouth does not seem to improve attacks in people with long-term asthma.
- Pain caused by nerve damage associated with cancer. Giving magnesium intravenously (by IV) seems to relieve pain caused by nerve damage due to cancer for several hours.
- Cerebral palsy. The best evidence to date suggests that giving magnesium to pregnant women before very preterm births can reduce the risk of cerebral palsy in the infant.
- Chronic fatigue syndrome (CFS). Administering magnesium as a shot seems to improve symptoms of fatigue. However, there is some controversy about its benefits.
- A lung disease called chronic obstructive pulmonary disease (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. Giving magnesium intravenously (by IV) seems to relieve cluster headaches.
- Colon and 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.
- Chest pain (angina) due to clogged arteries. Taking magnesium by mouth seems to reduce chest pain attacks and blood clots in people with coronary artery disease.
- Cystic fibrosis. Research shows that taking magnesium by mouth daily for 8 weeks improves lung strength in children with cystic fibrosis.
- Diabetes. Eating a diet with more magnesium is linked with a reduced risk of developing diabetes in adults and overweight children. Research on the effects of magnesium for people with existing type 2 diabetes shows conflicting results. In people with type 1 diabetes, magnesium might slow the development of nerve problems caused by diabetes.
- Fibromyalgia. Taking magnesium with malic acid (Super Malic tablets) by mouth seems to reduce pain related to fibromyalgia. Taking magnesium citrate daily for 8 weeks seems to improve some symptoms of fibromyalgia.
- 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 not related to loud noise. Injecting magnesium by IV might also help improve sudden hearing loss.
- 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.
- Metabolic syndrome (increased risk for diabetes and heart disease). 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 women and healthy young adults.
- Diseases of heart valves (mitral valve prolapse). Taking magnesium by mouth seems to reduce symptoms of mitral valve prolapse in people with low magnesium levels in their blood.
- Weak bones (osteoporosis). Taking magnesium by mouth seems to prevent bone loss in older women with osteoporosis. Also, taking estrogen along with magnesium plus calcium and a multivitamin supplement appears to increase bone strength in older women better than estrogen alone.
- Pain after a hysterectomy. Giving magnesium intravenously (by IV) seems to help reduce pain after a surgical procedure to remove the uterus called a hysterectomy. There is some evidence that a high magnesium dose of 3 grams followed by 500 mg per hour can reduce discomfort. However, lower doses do not seem to be effective and might actually increase pain.
- 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.
- 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:
- 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.
- Altitude sickness. Research suggests that taking magnesium citrate by mouth daily in three divided doses beginning 3 days before climbing a mountain and continuing until climbing down the mountain does not reduce the risk of sudden altitude sickness.
- Athletic performance. Some early research suggests that taking magnesium by mouth reduces the effects of sleep deprivation on athletic performance. Other research suggests that taking a magnesium supplement (Easymag, Sanofi-Aventis) by mouth daily for 12 weeks slightly improves walking speed in elderly women. Taking magnesium by mouth does not seem to increase energy or endurance during athletic activity.
- Chronic pain after an injury. Research suggests that using magnesium intravenously (by IV) for 4 hours each day for 5 days does not improve pain in people with chronic pain after an injury.
- Jellyfish stings. Research suggests that taking the medication fentanyl while receiving magnesium intravenously (by IV) does not reduce pain after a jellyfish sting more than fentanyl alone.
- Muscle cramps. Taking magnesium supplements does not seem to decrease the frequency or intensity of muscle cramps.
- Muscle strength. Some research suggests that applying a specific magnesium cream (MagPro) to muscles for one week does not improve muscle flexibility or endurance.
- Head trauma. Research suggests that magnesium does not improve the outcome or reduce the risk of death for people with a traumatic head injury.
- Sickle cell disease. Research shows that giving magnesium sulfate intravenously (by IV) every hour for 8 doses does not benefit children with sickle cell disease.
- Stillbirths. Taking magnesium supplements during pregnancy does not seem to decrease the risk of stillbirths.
- Tetanus. Taking magnesium does not seem to reduce the risk of death in people with tetanus compared to standard treatment. However, taking magnesium might reduce the amount of time spent in the hospital, although results are conflicting.
- Alcoholism. 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.
- Aluminum phosphide poisoning. Some research suggests that taking magnesium reduces the risk of death in people with aluminum phosphide poisoning. Other research suggests magnesium does not have this effect.
- Anxiety. Early research suggests that taking magnesium, hawthorn, and California poppy (Sympathyl, not available in the U.S.) might help treat mild to moderate anxiety disorder.
- Attention deficit-hyperactivity disorder (ADHD). Children with ADHD seem to have lower magnesium levels. Early research suggests that magnesium might help treat ADHD in children with low magnesium levels.
- Bipolar disorder. Early research suggests that taking a certain magnesium product (Magnesiocard) may have similar effects as lithium in some people with bipolar disorder.
- Heart disease. Research on the effects of magnesium intake in the diet on heart disease is inconsistent. Some research suggests that increasing magnesium intake in the diet is linked to a reduce risk of death related to heart disease. But not all research shows positive effects. Some research suggests that increasing magnesium intake in the diet does not affect heart disease risk. Other research suggests that there is no link between magnesium intake and heart disease.
- High blood pressure. Some research suggests that taking magnesium by mouth slightly reduces diastolic blood pressure (the bottom number in a blood pressure reading) in people with mild to moderate high blood pressure. Magnesium might not lower systolic blood pressure (the top number in a blood pressure reading).
- 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 not the long-term.
- Kidney stones. Taking magnesium by mouth might prevent the recurrence of kidney stones. But other medications such as chlorthalidone (Hygroton) may be more effective.
- Low 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.
- Mania. Early research suggests that taking magnesium by mouth plus the drug verapamil reduces manic symptoms better than just verapamil alone. Other early research suggests that giving magnesium intravenously (by IV) reduces the dose of other drugs needed to manage severe manic symptoms.
- Migraine headaches. Taking high doses of magnesium by mouth seems to reduce how often migraines occur, as well as their severity. But other research suggests that magnesium does not have any effect on migraines. Limited research suggests that using magnesium intravenously (by IV) might reduce migraines. Other research suggests that using magnesium by IV does not provide any relief.
- Multiple sclerosis (MS). Taking magnesium might reduce stiff or rigid muscles in people with MS.
- Nerve damage caused by the anticancer drug oxaliplatin. Research on the effects of magnesium on nerve damage caused by oxaliplatin is inconsistent. Some research shows that giving a calcium and magnesium infusion reduces nerve pain caused by this drug. But other research shows that it has no effect on preventing nerve damage or improving symptoms.
- Recovery after surgery. Some research suggests that taking a specific magnesium lozenge (Magnesium-Diasporal lozenge, Med Ilac, Istanbus, Turkey) by mouth 30 minutes before surgery reduces sore throat from the breathing tube.
- Pregnancy-related leg cramps. Research on the use of magnesium for treating leg cramps caused by pregnancy has been inconsistent. Some studies show that taking magnesium by mouth might reduce leg cramps during pregnancy. However, another study shows no benefit.
- Premature labor. 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. However, not all experts believe it is beneficial, and some research suggests it might cause more adverse effects.
- Restless leg syndrome. Taking magnesium by mouth might decrease the amount of movement and increase the amount of sleep in patients with restless leg syndrome. However, the role of magnesium, if any, in restless leg syndrome is uncertain. Some people with this condition have high levels of magnesium in their blood, while others have low magnesium levels.
- Stroke. There is inconsistent evidence about the effects of magnesium supplements or magnesium intake in the diet on stroke. Some evidence suggests that increasing magnesium intake in the diet might reduce the risk of stroke in men. But there is no proof that taking magnesium supplements will have the same effect. Some early research suggests that administering magnesium intravenously (by IV) might benefit people who have had a stroke. But other research suggests that it does not reduce the risk of death or disability in most people.
- Bleeding in 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.
- Sudden cardiac death. Some preliminary research suggests that higher levels of magnesium are linked with a lower chance of experiencing sudden cardiac death. However, it is not known if taking a magnesium supplement reduces the risk of sudden cardiac death. Giving magnesium intravenously does not seem to have a benefit.
- Poisoning from tricyclic antidepressant drugs. Early research shows that adding magnesium to an intravenous infusion does not help people with poisoning from tricyclic antidepressants.
- Lyme disease.
- Skin infections.
- Urinary incontinence.
- Other conditions.
MAGNESIUM Side Effects & Safety
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.
Special Precautions & Warnings:Pregnancy and breast-feeding: Magnesium is LIKELY SAFE for pregnant or breast-feeding women when taken in doses less than 350 mg daily. Magnesium is POSSIBLY SAFE when injected as a shot or intravenously (by IV) before delivery. Magnesium is POSSIBLY UNSAFE when 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.
Restless leg syndrome: People with restless leg syndrome might have high magnesium levels. But it's not clear if magnesium is the cause for this condition, as people with restless leg syndrome have also had magnesium deficiency.
Moderate Interaction Be 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), enoxacin (Penetrex), norfloxacin (Chibroxin, Noroxin), sparfloxacin (Zagam), trovafloxacin (Trovan), and grepafloxacin (Raxar).
- Antibiotics (Tetracycline antibiotics) interacts with MAGNESIUM
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).
- 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
Magnesium might decrease blood pressure. Taking magnesium with medication for high blood pressure might cause your blood pressure to go too low.
Some medications for high blood pressure 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).
The following doses have been studied in scientific research:
- 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 pregnant women age 14-18 years, the RDA is 400 mg; 19-30 years, 350 mg; 31-50 years, 360 mg. For lactating women 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 pregnant and breast-feeding women.
- For constipation: 8.75-25 grams of magnesium citrate has been used, usually as 150-300 mL in a 290 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: 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 magnesium deficiency: 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 chest pain due to clogged arteries: 800-1200 mg of magnesium oxide taken daily for 3 months 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 fibromyalgia: Magnesium hydroxide plus malic acid (Super Malic tablets) has been used. 300 mg of magnesium citrate daily for 8 weeks has also been used.
- For hearing loss: 167 mg of magnesium aspartate mixed in 200 mL lemonade, taken daily for 8 weeks or as a single dose, has been used.
- For high cholesterol: 1 gram of magnesium oxide daily for 6 weeks has been used.
- For metabolic syndrome: 365 mg of a specific magnesium aspartate product (Magnesiocard) taken daily for 6 months has been used.
- For disease of heart valves (mitral valve prolapse): 1200-1800 mg of magnesium carbonate taken daily for 5 weeks has been used.
- For 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.
- Pain after surgery: A specific magnesium lozenge (Magnesium-Diasporal lozenge, Med Ilac, Istanbul, Turkey) containing 610 mg magnesium citrate salt, taken 30 minutes before surgery, has been used.
- 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.
- For magnesium deficiency: 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 high blood pressure during pregnancy (pre-eclampsia and 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 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 pain caused by nerve damages associated 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 a lung disease called chronic pulmonary disease (COPD): 1.2 grams of magnesium sulfate has been given by IV after using an inhaler. 1.2-2 grams of magnesium sulfate in 100-150 mL of solution over 20 minutes has been used.
- For cluster headache: 1 gram of magnesium sulfate over 5 minutes has been used. Single 1 gram doses of magnesium sulfate have also been used.
- For pain after a hysterectomy: 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 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.
- 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.
- 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 high blood pressure during pregnancy (pre-eclampsia and eclampsia): 4 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 chronic fatigue syndrome (CFS): Solution containing 1 gram of magnesium sulfate has been given as a shot once weekly for 6 weeks.
- For a lung disease called chronic pulmonary disease (COPD): 2.5 mg of the drug salbutamol along with 2.5 mL of magnesium sulfate (151 mg per dose), inhaled three times at 30 minute intervals, has been used.
- 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.
- For cystic fibrosis: 300 mg of magnesium-glycine taken daily for 8 weeks has been used.
- 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.