Can magnesium oxide help with some health conditions?
Magnesium oxide is a form of magnesium salt. Most people get magnesium from food, but supplementation is sometimes needed. Cas 1309-42-8
Magnesium oxide is one of a few types of magnesium supplements you can get without a prescription. It is also an ingredient in some over-the-counter (OTC) medications. It is most commonly used to treat low magnesium levels and constipation. It has also been studied for its effects on blood pressure, type 2 diabetes, and migraines.
Magnesium oxide is generally safe, although it may cause stomach aches and diarrhea. The recommended daily magnesium intake from all sources is between 310 milligrams (mg) and 400 milligrams for younger adults and between 320 milligrams and 420 milligrams for older adults.
This article discusses the possible uses of magnesium oxide, including the side effects, risks, interactions, and how it differs from other forms of magnesium (such as magnesium citrate ).
Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian nutritionist, pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent a disease.
Magnesium oxide is a magnesium mineral supplement that has magnesium and oxygen ions.
Magnesium deficiency in the general population is uncommon, but low intakes (e.g., older adults) or losses caused by health conditions (e.g., gastrointestinal diseases, type 2 diabetes, alcohol misuse) can lead to a magnesium deficiency.
Early signs of a magnesium deficiency include:
When the deficiency gets worse, symptoms can include:
You can get magnesium through your diet and supplements. Before starting any supplements, please discuss them with your healthcare provider.
Magnesium is an ingredient in some laxatives (e.g., Philips' Milk of Magnesium). The supplement draws water into the intestines to soften stool, making it easier to pass (osmotic effect).
One randomized, double-blind, placebo-controlled trial looked at the effects of magnesium oxide in adults with chronic mild-to-moderate constipation. Seventeen people took magnesium oxide for 28 days and 17 took a placebo.
At the end of the study, magnesium oxide significantly improved participants’ overall symptoms, including spontaneous bowel movement, stool form, colonic transit time, and abdominal symptoms compared to taking the placebo.
Magnesium oxide should only be used as a short-term treatment for constipation. If you have constipation, talk to your healthcare provider about the best treatment for you. Call your provider if your constipation does not get better or gets worse after trying magnesium oxide.
Magnesium oxide might help reduce high blood pressure (hypertension) and lower the risk of stroke.
A review that looked at seven prospective studies found that diets high in magnesium can reduce diastolic blood pressure and may reduce the risk of stroke (especially ischemic strokes, which happen when an artery in the brain is blocked. This kind of stroke is often caused by high blood pressure).
Another systematic review of 49 studies on oral magnesium supplementation and blood pressure showed promising but conflicting results:
Diets high in magnesium have been associated with a lower risk of type 2 diabetes.
One long-term meta-analysis of seven studies including 286,668 people found that 100 milligrams per day in total magnesium intake significantly lowered the risk of diabetes.
Another meta-analysis of 13 studies demonstrated a dose-dependent association between magnesium intake and type 2 diabetes risk. However, this was only statistically significant in people who were overweight.
However, very few short-term clinical trials have been done on magnesium oxide’s effects on controlling type 2 diabetes. The American Diabetes Association (ADA) states there is not enough research to support using magnesium supplements to improve blood glucose in people with type 2 diabetes.
If you have diabetes, talk to your provider before starting magnesium oxide supplementation.
Magnesium oxide supplementation may reduce the number and intensity of migraines.
A randomized, double-blind crossover study showed that taking 500 milligrams of magnesium oxide appeared to be as effective as valproate sodium in preventing migraine attacks. Sixty-three people in the study took either magnesium oxide or valproate sodium.
The American Academy of Neurology and the American Headache Society concluded that magnesium therapy is "probably effective" for migraine prevention, but research is limited.
It’s also important to note that the typical dose of magnesium used for migraine prevention is higher than magnesium's tolerable upper limit (UL). Therefore, it should only be used under the supervision of a healthcare provider.
Please discuss the use of magnesium oxide supplements with your healthcare provider before taking them if you have migraines.
Other types of magnesium supplements include:
Consuming a supplement like magnesium oxide may have side effects. These side effects may be mild or severe.
Upset stomach and diarrhea are the most common side effects of magnesium oxide. Taking magnesium oxide with food can often prevent these side effects. If side effects do not get better or are getting worse, it is best to talk to your healthcare provider.
Severe allergic reactions to magnesium oxide are rare. However, seek immediate medical help if you develop:
People with kidney problems should ask their providers before starting magnesium oxide supplements. In addition, pregnant and lactating people, as well as children, should avoid magnesium oxide supplements because the risks to these groups are unknown.
Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your needs.
The following is the Recommended Dietary Allowance (RDA) for magnesium:
Magnesium oxide supplements should be taken by mouth with meals to reduce the chances of stomach upset. Do not crush or chew the supplements, as consuming them this way can increase the risk of side effects. If taken in liquid form, shake and measure the proper dose according to the instructions on the supplement's label.
Discuss your use of magnesium oxide with your provider to find out the safest and most effective amount to take for your needs.
It is possible to take too much magnesium oxide. Large doses of magnesium oxide can cause magnesium toxicity, but this is more likely in people with kidney problems.
Taking too much magnesium oxide may cause:
If you have any of these symptoms after taking magnesium oxide, seek medical care right away.
Magnesium oxide may prevent the absorption of several medications. Before starting magnesium oxide supplementation, please discuss the prescription and OTC medications, vitamins, or herbal supplements that you take with your healthcare provider.
Magnesium oxide might reduce how well the Parkinson's disease treatment Sinemet (levodopa and carbidopa) works. However, more studies are needed.
Other medications that can interact with magnesium oxide include:
Magnesium oxide may interact with the following supplements:
Other interactions may occur. Before starting magnesium oxide, ask your healthcare provider or pharmacist for a complete list of potential drug, supplement, and food interactions.
Carefully read a supplement's ingredient list and nutrition facts panel to know which ingredients and how much of each ingredient is included. Please review this supplement label with your healthcare provider to discuss any potential interactions with foods, other supplements, and medications.
Magnesium is found in many plant and animal foods and beverages, including green leafy vegetables (spinach), legumes, nuts, seeds, and whole grains. Usually, foods that are higher in fiber are rich in magnesium.
Magnesium oxide supplements are available OTC without a prescription. Magnesium oxide is sold under several brand names. Your healthcare provider or pharmacist can advise you on which brand might fit your unique situation and overall health.
Before starting a magnesium supplement, it is a good idea to have your magnesium levels checked by your provider. There is no way to know if the symptoms you are having are related to a magnesium deficiency, another nutritional deficiency, or an illness. You should tell your provider about any health conditions you have and all medications you’re taking to avoid interactions or adverse reactions.
Magnesium oxide is a type of magnesium. It’s often an ingredient in laxatives and supplements.
Getting enough magnesium is important for good health. Without it, the body cannot function properly. Eating magnesium-rich foods, like green leafy vegetables, legumes, nuts, seeds, and whole grains, is usually enough to get the magnesium you need.
It’s important to make sure you get enough magnesium without getting too much. You should always talk to your provider before starting any supplement. If you think you have low magnesium levels, ask your provider to check them.
The best way to get magnesium is through your diet and eating a variety of magnesium-rich foods, such as spinach, legumes, nuts, seeds, and whole grains.
Supplements are an option for maintaining magnesium levels in people whose levels remain low despite diet changes. Please talk to your healthcare provider before starting a magnesium oxide supplement.
A healthcare provider can assist you in determining if magnesium oxide supplements are needed for maintaining and/or increasing magnesium. A blood test is usually used to check the level of magnesium in your blood.
Anyone who thinks their magnesium is low should talk to their healthcare provider before starting a supplement.
National Institutes of Health Office of Dietary Supplements. Magnesium fact sheet for health professionals.
Mori H, Tack J, Suzuki H. Magnesium oxide in constipation. Nutrients. 2021;13(2):421. doi:10.3390/nu13020421
Mori S, Tomita T, Fujimura K, et al. A randomized double-blind placebo-controlled trial on the effect of magnesium oxide in patients with chronic constipation. J Neurogastroenterol Motil. 2019;25(4):563-575. doi:10.5056/jnm18194.
Larsson SC, Orsini N, Wolk A. Dietary magnesium intake and risk of stroke: a meta-analysis of prospective studies. Am J Clin Nutr. 2012; 95(2):362-366. doi:10.3945/ajcn.111.022376
Rosanoff A, Costello RB, Johnson GH. Effectively prescribing oral magnesium therapy for hypertension: a categorized systematic review of 49 clinical trials. Nutrients. 2021;13(1):195. doi:10.3390/nu13010195
Larsson SC, Wolk A. Magnesium intake and risk of type 2 diabetes: a meta-analysis. J Intern Med. 2007;262(2):208-214. doi:10.1111/j.1365-2796.2007.01840.x
Dong JY, Xun P, He K, Qin LQ. Magnesium intake and risk of type 2 diabetes: meta-analysis of prospective cohort studies. Diabetes Care. 2011;34(9):2116-2122. doi:10.2337/dc11-0518
Evert AB, Boucher JL, Cypress M, et al. Nutrition therapy recommendations for the management of adults with diabetes. Diabetes Care. 2013;36:3821-3842. doi:10.2337/dc13-2042
Karimi N, Razian A, Heidari M. The efficacy of magnesium oxide and sodium valproate in prevention of migraine headache: a randomized, controlled, double-blind, crossover study. Acta Neurologica Belgica. 2019;121:167-173. doi:10.1007/s13760-019-01101-x
Blancquaert L, Vervaet C, Derave W. Predicting and testing bioavailability of magnesium supplements. Nutrients. 2019;11(7):1663. Published 2019 Jul 20. doi:10.3390/nu11071663
Lindberg JS, Zobitz MM, Poindexter JR, Pak CY. Magnesium bioavailability from magnesium citrate and magnesium oxide. J Am Coll Nutr. 1990;9(1):48-55. doi:10.1080/07315724.1990.10720349
Food and Drug Administration. Magnesium lactate.
Ferreira I, Ortigoza Á, Moore P. Magnesium and malic acid supplementation for fibromyalgia.Magnesium and malic acid supplements for fibromyalgia.Medwave.2019;19(4):e7Published May 28, 2019. doi:10.5867/medwave
Consumer Lab. What is the benefit of magnesium orotate compared to other forms of magnesium?.
Azmeen A, Condit D, Rosenberg E, et al. A case of catastrophic magnesium overdose. 2021;160(4):A954-A955. doi:10.1016/j.chest.2021.07.889
National Center for Biotechnology Information. PubChem Compound Summary for CID 151152, Threonic acid.
National Cancer Institute. Definition of magnesium l-threonate.
Kashihara Y, Terao Y, Yoda K, et al. Effects of magnesium oxide on pharmacokinetics of L-dopa/carbidopa and assessment of pharmacodynamic changes by a model-based simulation. Eur J Clin Pharmacol. 2019;75(3):351-361. doi:10.1007/s00228-018-2568-4
Firoz M, Graber M. Bioavailability of US commercial magnesium preparations. Magnes Res. 2001;14(4):257-262.
Lee S, Park HK, Son SP, Lee CW, Kim IJ, Kim HJ. Effects of oral magnesium supplementation on insulin sensitivity and blood pressure in normo-magnesemic nondiabetic overweight Korean adults. Nutr Metab Cardiovasc Dis. 2009;19(11):781-788. doi:10.1016/j.numecd.2009.01.002
U.S. National Library of Medicine: National Center for Biotechnology Information. PubChem Compound Database. Magnesium oxide.
By Alena Clark, PhD Alena Clark, PhD, is a registered dietitian and experienced nutrition and health educator
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