- Magnesium fact sheet for health professionals Office of Dietary Supplements
- Magnesium Linus Pauling Institute
- List of foods high in magnesium US Department of Agriculture
- Comparison of the mineral content of tap water and bottled waters PubMed Central
- Magnesium National Academics Press
- Fulop, T. et al, Hypomagnesemia Emedicine
- Novello, NP et al, Hypermagnesemia Emedicine
- Banai, S., 1993, Drug therapy for torsades de pointes PubMed
- Douglas S., 2002, Premenstrual syndrome: Evidence based treatment in family practice PubMed Central
- Sodium picosulfate, magnesium oxide, and anhydrous citric acid (PREPOPIK) for oral solution US Department of Veteran Affairs
- Recurrent nephrolithiasis in adults: comparative effectiveness of preventive medical strategies Agency for Healthcare Research and Quality
- Rowe B.H., 2009, Inhaled magnesium sulfate in the treatment of acute asthma Cochrane Summaries
- Mauskop, A. et al, 1995, Intravenous magnesium sulfate relieves cluster headaches in patients with low serum ionized magnesium levels PubMed
- Hoshino, K. et al, 2004, Optimal administration dosage of magnesium sulfate for torsades de pointes in children with long QT syndrome PubMed
- Mohammed S., 2007, Intravenous and nebulised magnesium sulphate for acute asthma: systematic review and meta-analysis Emergency Medicine Journal
- Farouk, S., 2008, Pre-incisional epidural magnesium provides pre-emptive and preventive analgesia in patients undergoing abdominal hysterectomy British Journal of Anesthesia
- Chien, P.F., 1996, Magnesium sulphate in the treatment of eclampsia and pre-eclampsia: an overview of the evidence from randomized trials PubMed
- Peikert, A. at al, 1996, Prophylaxis of migraine with oral magnesium: results from a prospective, multi-center, placebo-controlled and double-blind randomized study PubMed
- Magnesium side effects Drugs.com
- Dietary reference intakes (DRIs): Recommended dietary allowances and adequate intakes, vitamins Institute of Medicine
- Nielsen, F.H. et al, 2006, Update on the relationship between magnesium and exercise Magnesium Research
- Conzolatio, C.F. et al, 1963, Excretion of sodium, potassium, magnesium and iron in human sweat and the relation of each to balance and requirements The Journal of Nutrition
- Beyer, F.R. et al, 2009, Combined calcium, magnesium and potassium supplementation for the management of primary hypertension in adults Cochrane Summaries
- Mazzaro, C.C. et al, 2014, Dietary interventions and blood pressure in Latin America: systematic review and meta analysis PubMed Central
- Sabatier, M. et al, 2002, Meal effect on magnesium bioavailability from mineral water in healthy women American Journal of Clinical Nutrition
- Van Dam, M.R. et al, 2006, Dietary calcium and magnesium, major food sources and risk of diabetes 2 in the U.S. black women Diabetes Care
- Dong, J-Y et al, 2011, Magnesium intake and risk of type 2 diabetes Diabetes Care
- Meyer, K.A. et al, 2000, Carbohydrates, dietary fiber and incident type 2 diabetes in older women PubMed
- Walker, A.F. et al, 2003, Mg citrate found more bioavailable than other Mg preparations in a randomized, double‐blind study Magnesium Research
- Fine, KD et al, 1991, Intestinal absorption of magnesium from foods and supplements PubMed Central
- Bøhmer, T. et, 1990, Bioavailability of oral magnesium supplementation in female students evaluated from elimination of magnesium in 24-hour urine PubMed
- Schuette, SA et al, 1994, Bioavailability of magnesium diglycinate in patients with ileal resection PubMed
- Firoz, M. et al, 2001, Bioavailability of US commercial magnesium preparations PubMed
- Magnesium and depression: a systematic review Maney Online
- Derom, ML et al, 2013, A systematic review of magnesium therapy for treating ADHD Aimjournal
- Aguilar, F. et al, 2009, Orotic acid salts as sources of orotic acid and various minerals added for nutritional purposes to food supplements European Food Safety Authority
- Waring, RH, Report on absorption of magnesium sulfate (Epsom salts) across the skin Epsomsaltcouncil
- Morris, ME et al, 1987, Absorption of magnesium from orally administered magnesium sulfate in man PubMed
- Aguilar, F. et al, 2009, Calcium ascorbate, magnesium ascorbate and zinc ascorbate added for nutritional purposes in food supplements European Food Safety Authority
- Holtmeier, W. eta al, 2007, On-demand treatment of acute heartburn with the antacid hydrotalcite compared with famotidine and placebo: randomized double-blind cross-over study PubMed
- Kwan, I. et al, 2008, Premenstrual syndrome American Family Physician
- Select committee on GRAS substances (SCOGS) opinion: Magnesium gluconate Food and Drug Administration
- Magnesium supplementation GlobalRPh
- Lindberg, JS et al, 1990, Magnesium bioavailability from magnesium citrate and magnesium oxide PubMed
- Schwartz R et al, 1973, Metabolic responses of adolescent boys to two levels of dietary magnesium and protein. I. Magnesium and nitrogen retention The American Journal of Clinical Nutrition
- Percentage of mineral elements and relative bioavailability Purdue University
- Barclay, L., 2012, Long-term PPIs use associated with low magnesium Medscape
- Withowski, M. et al, 2011, Methods of assessment of magnesium status in humans: a systematic review Magnesium Research
- Jahnen-Dechent, W. et al, 2012, Magnesium basics Clinical Kidney Journal
- Ramkumar, D. et al, 2005, Efficacy and safety of traditional medical therapies for chronic constipation: systematic review PubMed
- Wexner SD et al, 2006, A consensus document on bowel preparation before colonoscopy National Guideline Clearinghouse
- 2000, Migraine and cluster headache: nonsurgical management Aetna
- Mauskop, A. et al, 2002, Intravenous magnesium sulfate rapidly alleviates headaches of various types Wiley Online Library
- Beithon, J. et al, 2013, Diagnosis and treatment of headache National Guideline Clearinghouse
- Paban NM eta al, 2012, To evaluate the efficacy of intrathecal magnesium sulphate for hysterectomy under subarachnoid block with bupivacaine and fentanyl: A prospective randomized double blind clinical trial PubMed Central
- Evert, AB et al, 2013, Nutrition therapy recommendations for the management of adults with diabetes Diabetes Care
- Burke, RA et al, 2012, Review of the treatment of restless legs syndrome: focus on gabapentin enacarbil PubMed Central
- Sebo, P. et al, 2014, Effect of magnesium therapy on nocturnal leg cramps: a systematic review of randomized controlled trials with meta-analysis using simulations Family Practice
- Beard, S. et al, 2003, Treatments for spasticity and pain in multiple sclerosis: a systematic review PubMed Health
- Fibromyalgia and complementary health approaches National Center for Complementary and Alternative Medicine
- Chambers, D. et al, 2006, Interventions for the treatment, management and rehabilitation of patients with chronic fatigue syndrome/myalgic encephalomyelitis: an updated systematic review Journal of the Royal Society of Medicine
- Fulop, T. et al, Hypomagnesemia treatment Emedicine
- 2009, Colonoscopy preparation American Society for Gastrointestinal Endoscopy
- Acute migraine treatment in emergency setting Agency for Healthcare Research and Quality
- Lakhan, SE et al, 2009, Nutritional and herbal supplements for anxiety and anxiety-related disorders: systematic review Nutrition Journal
- Duley, L. et al, 2010, Magnesium sulphate and other anticonvulsants for women with pre-eclampsia PubMed
- Makrides, M. et al, 2014, Magnesium supplementation in pregnancy PubMed
- Makrides, M et al, 2001, Magnesium supplementation in pregnancy PubMed
- Witlin, AG et al, 1998, Magnesium sulfate therapy in preeclampsia and eclampsia PubMed
- Li, J., et al, 2009, Intravenous magnesium for acute myocardial infarction Cochrane Summaries
- Garrison, SR et al, 2012, Magnesium for muscle cramps Cochrane Summaries
- Lanza, FL et al, 1986, Effectiveness of foaming antacid in relieving induced heartburn PubMed
- Holtmeier, W. et al, 2007, On-demand treatment of acute heartburn with the antacid hydrotalcite compared with famotidine and placebo: randomized double-blind cross-over study PubMed
- Shepherd, J. et al, 2008, Intravenous magnesium sulphate and sotalol for prevention of atrial fibrillation after coronary artery bypass surgery: a systematic review and economic evaluation PubMed Health
- Aguilar F. eta al, 2009, Safety of magnesium taurinate added for nutritional purposes as a source of magnesium in food supplements and bioavailability of magnesium from this source, based on the supporting dossier European Food Safety Authority
- Garcia-Lopez, R. et al, 2009, New therapeutic approach to Tourette Syndrome in children based on a randomized placebo-controlled double-blind phase IV study of the effectiveness and safety of magnesium and vitamin B6 Trials
- Seeliq, MS., 1994, Consequences of magnesium deficiency on the enhancement of stress reactions; preventive and therapeutic implications (a review) PubMed
- Galland, L., 1992, Magnesium, stress and neuropsychiatric disorders PubMed
- Aguilar, F. eta al, 2008, Magnesium aspartate, potassium aspartate, magnesium potassium aspartate, calcium aspartate, zinc aspartate, and copper aspartate as sources for magnesium, potassium, calcium, zinc, and copper added for nutritional purposes to food supplements European Foods Safety Authority
- 2013, Magnesium sulfate: drug safety communication – recommendation against prolonged use in pre-term labor Food and Drug Administration
- Fawcett, WJ et al, 1999, Magnesium physiology and pharmacology British Journal of Anesthesia
- Terblanche, S. et al, 1992, Failure of magnesium supplementation to influence marathon running performance or recovery in magnesium-replete subjects PubMed
- Dupont, C. eta al, 2013, Efficacy and safety of a magnesium sulfate–rich natural mineral water for patients with functional constipation Clinical Gastroenterology and Hepatology
- Larsson, SC et al, 2012, Dietary magnesium intake and risk of stroke: a meta-analysis of prospective studies American Journal of Clinical Nutrition
- Dai, Q. eta al, 2013, Modifying effect of calcium/magnesium intake ratio and mortality: a population-based cohort study BMJ Open
- Mauskop, A. et al, 2002, Serum ionized magnesium levels and serum ionized calcium/ionized magnesium ratios in women with menstrual migraine PubMed
- Sluijs, I. et al, 2014, Intakes of potassium, magnesium, and calcium and risk of stroke Stroke
- Diabetes and dietary supplements National Center of Complementary and Alternative Medicine
- Walker, AF et al, 2003, Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study PubMed
- Golf, S., 2006, Pharmacokinetics and bioavailability of magnesium compounds Pharmazeutische-zeitung.de (translated to English)
What is magnesium and what does it do in the body?
Magnesium is an essential mineral necessary for the functioning of the nerves, muscles, heart and gut and for maintaining bone structure [1,2]. Magnesium is also necessary for proper functioning of calcium, potassium and vitamin D .
Magnesium is a natural calcium antagonist, for example, calcium enables muscle contraction and magnesium muscle relaxation [49,81].
A chemical symbol for magnesium is Mg.
How much magnesium do you need?
The Recommended Dietary Allowance (RDA) for magnesium for adults is 350-400 mg/day.
Chart 1. Recommended Dietary Allowance (RDA) for magnesium
|Infants 0-6 months||30 (AI*)|
|Infants 7-12 months||75 (AI*)|
|Pregnancy and breastfeeding||310-400|
Chart 1 source: Institute of medicine (IOM)  *AI = Adequate Intake. Breast milk of healthy mothers should provide enough magnesium for exclusively breastfed infants 0-6 months of age [3,20].
Major sources of magnesium are foods high in fiber, such as whole-grain cereals, green leafy vegetables (chlorophyll contains Mg), legumes, nuts and seeds, and certain fish. Meat, poultry and dairy are low in magnesium.
Picture 1. Examples of foods high in magnesium
Chart 2. List of Foods High in Magnesium
|PLANT FOODS||Magnesium (mg)|
|Formulated bar, certain brands (2 oz, 57 g)||170|
|Quinoa (1 cup, 185 g)||120|
|Brown rice (1 cup, 195 g)||90|
|Buckwheat groats (1 cup, 170 g)||90|
|Oat bran (1 cup, 220 g)||90|
|Spinach, Swiss chard (1/2 cup, 90 g)||80|
|Nuts (almonds, cashews, hazelnuts, peanuts); seeds (pumpkin, squash, sunflower) (1 oz, 28 g)||50-80|
|Soybeans (1/2 cup, 85 g)||70|
|Oatmeal, instant, fortified (1 cup, 234 g)||60|
|Bread, whole wheat (1 slice, 60 g)||60|
|Beet greens (1/2 cup, 70 g)||50|
|Figs, dried (1/2 cup, 75 g)||50|
|Molasses (1 tbsp, 20 g)||50|
|Dark chocolate (1 oz, 28 g)||50|
|Beans, peas, lentils (1/2 cup, 120 g)||30-50|
|Avocado, cubes (1 cup, 150 g)||45|
|Potato (1 cup, 160 g)||30|
|Banana (1 medium, 120 g)||30|
|Okra (1/2 cup, 80 g)||30|
|Bottled water in the North America (1 cup, 237 mL) [Mg sulfate and bicarbonate]||0-30|
|Drinking tap water in the North America (1 cup, 237 mL)||0-11|
|Fish: pollock, salmon (chinook), mackerel (3 oz, 85 g)||70-100|
|Milk (1 cup, 237 mL)||35|
|Fish: halibut, sardines (3 oz, 85 g)||~30|
Chart 2. source: US Department of Agriculture (USDA.gov)  NOTE: All foods listed are ready to eat.
About 30-50% of magnesium from foods and water is absorbed, mainly in the small intestine [1,5,25].
Are there any benefits of a high-magnesium diet?
Constipation. Magnesium-rich mineral water can help prevent constipation .
High blood pressure. In several studies in individuals with hypertension, high magnesium intake from foods was only weakly associated with lower blood pressure [2,24].
Heart disease. Results of several large studies are conflicting: high magnesium intake may or may not have a protective effect on the heart .
Stroke. In one large 2014 observational study, high magnesium intake was associated with lower risk of stroke .
Diabetes mellitus. In many, but not all, studies, consuming foods high in magnesium, mainly from whole grains, was associated with lower risk of diabetes mellitus type 2 [2,26,27,28,88].
Results of above studies do not show a clear cause-effect relationship between magnesium intake and diseases because foods high in magnesium are often high in fiber, potassium and other nutrients that might affect.
Normal Blood Levels
A normal blood magnesium level range for adults is 1.7-2.1 mg/dL (0.7-0.9 mmol/L or 1.4-1.8 mEq/L) .
Magnesium Deficiency and Low Blood Magnesium Levels (Hypomagnesemia)
Magnesium deficiency means decreased magnesium body stores, which may or may not lead to low blood magnesium levels or hypomagnesemia (<1.7 mg/dL or 0.7 mmol/L). In healthy people who eat regularly, diet low in magnesium does not likely result in low blood magnesium levels.
Causes and Risk Factors:
- Poor magnesium intake in chronic alcoholism, anorexia nervosa, prolonged starvation and old age
- Poor magnesium absorption in celiac disease, Crohn’s disease, surgical removal of a large part of the small intestine, chronic pancreatitis, prolonged diarrhea or frequent vomiting, and possibly in protein malnutrition 
- Excessive loss of magnesium through the urine in poorly controlled diabetes, kidney disorders, hypercalcemia or hyperaldosteronism
- Long-term treatment with certain diuretics, proton-pump inhibitors or PPIs (omeprazole or esomeprazole magnesium for >1 year) , antimicrobials (amphotericin B, foscarnet), chemotherapy (cisplatin), immunosuppressants (cyclosporine)
- Prolonged physical or emotional stress 
- Increased magnesium loss through sweat during prolonged athletic training may result in slight magnesium deficiency but not likely in low blood magnesium levels [6,21,22].
- Acute drop of blood magnesium levels:
- Alcohol withdrawal, acute pancreatitis, severe injury, surgery
- Refeeding syndrome: Glucose injection after prolonged starvation (in alcoholics), or insulin injection in previously untreated diabetes mellitus
Symptoms and Signs:
- Mild hypomagnesemia: loss of appetite, nausea, fatigue, constipation
- Severe hypomagnesemia: numbness, tingling around the mouth and in fingers, hyperventilation, muscle twitches or cramps (tetany), shaking (tremor), teeth grinding, difficulty breathing, migraine attacks, chest pain (due to spasms of the coronary arteries), abnormal heart rhythm (arrhythmia), seizures, hearing loss and tinnitus, hallucinations, coma or, rarely, death .
Complications: hypocalcemia, hypokalemia, phosphate deficiency
Long-term magnesium deficiency might increase the risk of diabetes 2 (insulin resistance)  and stroke .
Assessment of magnesium status. Normal blood magnesium levels do not already mean normal body magnesium stores. For example, a chronic alcoholic may have normal blood magnesium levels but severe magnesium depletion ─ low magnesium levels within the cells and in the bones. In the body of an adult (70 kg), about 25 grams of magnesium is stored, mainly in bones and muscles . Assessment of total body magnesium may include checking magnesium levels in the blood serum, red blood cells, urine or in a sample of muscle or mouth mucosa (biopsy) . None of these methods are completely reliable and are rarely used.
Treatment. For magnesium deficiency and mild hypomagnesemia: oral magnesium supplements. For severe hypomagnesemia: magnesium injection and, in case of abnormal heart rhythm, intravenous calcium chloride or gluconate as an antidote.
Magnesium can be part of multivitamin/mineral supplements or combined with calcium or vitamin B6 (pyridoxine). Available oral forms: tablets, effervescent tablets, extended-release tablets, chewables, capsules, powder for solution, liquids, syrups.
From the limited and conflicting data available (Chart 3), we are not able to conclude which magnesium supplement is most effective. One author from a German Pharmazeutische Zeitung beieves that all magnesium supplements have about the same bioavailability .
Chart 3. Oral magnesium supplements available OTC
|COMPOUND||% ELEMENTAL Mg*||BIOAVAILABILITY||SAFETY, PREGNANCY CATEGORY|
|Chelates with non-amino organic acids|
|Ascorbate (Mg + ascorbic acid or vitamin C)||6.4%||Well absorbed ||Considered safe by EFSA |
|Citrate (Mg + citric acid)||16%||Well absorbed (30%) [44,89]||Also used as a laxative. Pregnancy category: C|
|Citramate (Mg + citric acid + malic acid)||Probably absorbed similar to citrate and malate|
|Potassium-magnesium citrate (Mg + K + citric acid)||Well absorbed [39,40]|
|Fumarate (Mg + fumaric acid)||Well absorbed |
|Gluconate (Mg + gluconic acid)||5.4%||Well absorbed (20%) ||Considered safe by FDA . Pregnancy category: C|
|Lactate (Mg + lactic acid)||12%||Well absorbed ||Pregnancy category: C|
|Malate (Mg + malic acid)||6.5%|
|Pidolate (Mg + pidolic acid)||8.7%|
|Salicylate (Mg + salicylic acid)||12%||?||To treat rheumatoid arthritis. Overuse of salicylates can cause peptic ulcer and kidney damage. Pregnancy category: C|
|Threonate (Mg + threonic acid)||7.7%|
|Chelates with amino acids|
|Arginate (Mg + arginic acid)||30%**||Pregnancy category: C|
|L-Aspartate (Mg + aspartic acid)||20%||Well absorbed [33,44]||Aspartate is an excitatory neurotransmitter. EFSA: “Magnesium aspartate may be of safety concern.”  Pregnancy category: C|
|Glutamate (Mg + glutamic acid)||Glutamate is an excitatory neurotransmitter. Pregnancy category: C|
|Glycinate (Mg + glycine)||5.5%||?||Pregnancy category: C|
|Lysinate (Mg + lysine)||Pregnancy category: C|
|Orotate (Mg + orotic acid)||6%||Bioavailability is probably comparable to other similar Mg supplements .||Expensive. EFSA: “…in the light of the tumor-promoting effect of orotic acid in animal experimentation… the use of orotate as a source of minerals…is of safety concern” . Pregnancy category: C|
|Taurate or Taurinate (Mg + taurine)||9%||Bioavailability is probably comparable to other similar Mg supplements .||Pregnancy category: C|
|Inorganic magnesium compounds|
|Carbonate (Mg + carbonic acid)||40-45%||“High” bioavailability ||Mainly used as an antacid and food additive. Pregnancy category: not classified|
|Magnesium chloride||12%||Well absorbed ||Pregnancy category: C|
|Magnesium hydroxide or milk of magnesia||42%||Conflicting reports: from poor to good absorption [31,43]||Used as an antacid and laxative. Pregnancy category: Not classified|
|Magnesium oxide||60%||4-23% absorption but “extremely low” bioavailability [33,44,89]||Used as an antacid or laxative. Pregnancy category: C|
|Magnesium sulfate or Epsom salt (Mg +sulfuric acid)||10-17%||Well absorbed (50%) from mineral water ||Used as a laxative. Pregnancy category: A|
|Enteric-coated (any compound)||Probably less well absorbed than regular formulations |
Chart 3. sources: GlobalPRh , Purdue University , PubMed [29,30,31,32,33], Drugs.com, producers, EFSA (European Food Safety Authority), FDA (Food and Drug Administration in the US). *Elemental Mg is the actual magnesium in the supplement.
“Natural magnesium” is a commercial term for magnesium chloride obtained from sea. “Organic magnesium” is a commercial term for magnesium chelates with organic acids (see Chart 3 above). Organic magnesium supplements are artificially produced and do not meet the criteria for “USDA organic” substances. “Ionic magnesium” is a mixture of various salts, such as magnesium chloride and sulfate, in a liquid form. There is no scientific data about eventual superiority of ionic magnesium over other magnesium forms.
Topical (Transdermal) Magnesium
Magnesium oil contains magnesium chloride. It is available as a spray, gel, lotion or bath flakes. It is not known if magnesium from magnesium oil can be absorbed through the skin in significant amounts.
Epsom salt. A small amount of magnesium is absorbed through the skin during bathing in water with added Epsom salt (magnesium sulfate) .
An injection of magnesium sulfate, or rarely, magnesium chloride or gluconate, into a vein or muscle (a shot) is used to treat severe hypomagnesemia.
Other Magnesium Uses
- Antacids for heartburn in gastroesophageal reflux disease ─ GERD: magnesium carbonate, hydroxide, phosphate, trisilicate
- Laxatives: magnesium citrate, oxide, hydroxide (milk of magnesia), sulfate (Epsom salt)
- Food additives: magnesium acetate, phosphate, silicate (talc), trisilicate
- Magnesium bromide is used as a sedative and anticonvulsant.
- Magnesium mandelate is used as an urinary antiseptic.
- Magnesium salicylate is an analgesic often used in rheumatoid arthritis.
- Magnesium stearate is used as a flow agent in liquid dietary supplements.
What are magnesium supplements good for?
Oral magnesium supplements are EFFECTIVE for:
- Magnesium deficiency 
Oral magnesium supplements are POSSIBLY EFFECTIVE for:
- Sour stomach, dyspepsia, heartburn in gastroesophageal reflux disease ─ GERD (Aluminium magnesium hydroxide carbonate hydrate or hydrotalcite or foaming antacid) [40,72,73]
- Preparation of the bowel for colonoscopy or surgery (magnesium citrate, hydroxide, sulfate or phosphate); not optimally effective when used alone [10,51,63]
Intravenous injections of magnesium sulfate are possibly effective for:
- Reducing seizures in women with high blood pressure during pregnancy (eclampsia) [17,66]
- Certain types of irregular hear rhythm (arrhythmia) [8,74]
- Decreasing symptoms of acute asthma in children but not in adults 
- Relieving pain after a womb removal (hysterectomy) [16,55]
Oral magnesium supplements are POSSIBLY INEFFECTIVE in increasing exercise performance .
There is INSUFFICIENT EVIDENCE about magnesium supplements effectiveness in preventing or treatment of anxiety , asthma (inhaled magnesium , attention deficit-hyperactivity disorder (ADHD) , cluster headache [13,53,54], chronic constipation , chronic fatigue syndrome (CFS) , depression , diabetes type 2 , fibromyalgia , heart attack , high blood pressure , high blood pressure in pregnancy (pre-eclampsia) [67,68,69], kidney stones , leg muscle cramps in elderly or during pregnancy [58,71], migraine [52,54,64], multiple sclerosis (MS) , osteoporosis [1,2], premenstrual syndrome (PMS) [9,41], restless leg syndrome , tics (Tourette syndrome)  or stroke .
Magnesium Safety: Side Effects, Toxicity
The Tolerable Upper Intake Level (UL)–the dose unlikely causing side effects–for supplemental magnesium for 1-3 years old children is 65 mg/day, for 4-8 years 110 mg/day, and for 9 years and older children and adults 350 mg/day . Magnesium from foods even in amounts exceeding 350 mg/day does not likely cause side effects.
The main side effect of oral–but not intravenous–magnesium supplements is diarrhea. Magnesium overdose may cause thirst, fainting, drowsiness, confusion, slow heart beat, drop of the blood pressure (hypotension), muscle weakness or difficulty breathing . Magnesium sulfate injection can cause skin flushing and irritation at the injection site. Magnesium sulfate is pregnancy category D; it should not be used to stop preterm labor because it can harm the fetus . Allergic reactions to magnesium supplements with difficult breathing and facial swelling are possible.
If you are pregnant or breastfeeding and intend to use magnesium supplements, speak with your doctor. For pregnancy categories of supplements check Chart 3 above.
Who may need to avoid magnesium supplements?
- Individuals with increased blood magnesium levels, kidney disease, myasthenia gravis or other neurological disorders
- Individuals allergic to magnesium compounds
For treatment of magnesium deficiency, oral doses up to 350 mg of elemental magnesium per day are used.
High Blood Magnesium Levels (Hypermagnesemia)
Hypermagnesemia means blood magnesium levels above 2.1 mg/dL or 0.9 mmol/L. Hypermagnesemia does not likely result from eating foods high in magnesium.
- Kidney failure in combination with overdose of magnesium supplements, antacids or laxatives
- Other: cancer, lithium therapy, hypothyroidism, Addison’s disease, genetic metabolic disorders, milk alkali syndrome, extensive burns, shock, sepsis, severe muscle damage (rhabdomyolysis, crush syndrome)
Symptoms and Signs
Symptoms and signs, which occur only in severe hypermagnesemia, may include muscle weakness or paralysis, dizziness, low blood pressure (hypotension), abnormal heart rhythm (arrhythmia), heart attack, coma or even death.
Calcium : Magnesium Ratio
In several observational studies, low Ca/Mg intake ratio (<1.7) was associated with increased mortality in both women and men , but high Ca/Mg intake ratio was associated with increased risk of colorectal cancer, and high blood Ca/Mg ratio was associated with increased risk of menstrual migraine . Results of these studies do not allow any firm conclusion about the importance of Ca/Mg ratio.
Magnesium ─ Drugs Interactions
Supplements that might reduce the absorption of magnesium if taken together: zinc or calcium supplements in high doses.
Drugs and supplements that may increase magnesium levels: certain diuretics (amiloride, spironolactone) and probably vitamin D (slightly) [1,2]. For other magnesium-drug interactions check the information leaflet within the supplement package.
- Hydrogenated starch hydrolysates (HSH)
- Fructo-oligosaccharides (FOS)
- Galacto-oligosaccharides (GOS)
- Human milk oligosaccharides (HMO)
- Isomalto-oligosaccharides (IMO)
- Mannan oligosaccharides (MOS)
- Raffinose, stachyose, verbascose
- SOLUBLE FIBER:
- Acacia (arabic) gum
- Beta mannan
- Carageenan gum
- Carob or locust bean gum
- Fenugreek gum
- Gellan gum
- Glucomannan or konjac gum
- Guar gum
- Karaya gum
- Psyllium husk mucilage
- Resistant starches
- Tara gum
- Tragacanth gum
- Xanthan gum
- INSOLUBLE FIBER:
- Chitin and chitosan
- Aspartic acid
- Glutamic acid
- FATTY ACIDS
- Alpha-linolenic acid (ALA)
- Eicosapentaenoic (EPA) and Docosahexaenoic acid (DHA)
- Arachidonic acid (AA)
- Linoleic acid
- Conjugated linoleic acid (CLA)
- Short-chain fatty acids (SCFAs)
- Medium-chain fatty acids (MCFAs)
- Long-chain fatty acids (LCFAs)
- Very long-chain fatty acids (VLCFAs)
- Vitamin A - Retinol and retinal
- Vitamin B1 - Thiamine
- Vitamin B2 - Riboflavin
- Vitamin B3 - Niacin
- Vitamin B5 - Pantothenic acid
- Vitamin B6 - Pyridoxine
- Vitamin B7 - Biotin
- Vitamin B9 - Folic acid
- Vitamin B12 - Cobalamin
- Vitamin C - Ascorbic acid
- Vitamin D - Ergocalciferol and cholecalciferol
- Vitamin E - Tocopherol
- Vitamin K - Phylloquinone
- Flavanols: Proanthocyanidins
- Flavanones: Hesperidin
- Flavonols: Quercetin
- Flavones: Diosmin, Luteolin
- Isoflavones: daidzein, genistein
- Caffeic acid
- Chlorogenic acid
- Tannic acid
- Alcohol chemical and physical properties
- Alcoholic beverages types (beer, wine, spirits)
- Denatured alcohol
- Alcohol absorption, metabolism, elimination
- Alcohol and body temperature
- Alcohol and the skin
- Alcohol, appetite and digestion
- Neurological effects of alcohol
- Alcohol, hormones and neurotransmitters
- Alcohol and pain
- Alcohol, blood pressure, heart disease and stroke
- Women, pregnancy, children and alcohol
- Alcohol tolerance
- Alcohol, blood glucose and diabetes
- Alcohol intolerance, allergy and headache
- Alcohol and psychological disorders
- Alcohol and vitamin, mineral and protein deficiency
- Alcohol-drug interactions
- Moderate, heavy, binge drinking
- Alcohol intoxication
- Alcohol poisoning
- Alcohol and gastrointestinal tract
- Alcoholic liver disease
- Long-term effects of excessive alcohol drinking
- Alcohol craving and alcoholism
- Alcohol withdrawal