Magnesium What It Is How Much You Need and Where to Find It Everyday Health MenuNewslettersSearch Diet & Nutrition Magnesium What It Is How Much You Need and Where to Find It By Julie Lichty Balay, RD, CSSDMedically Reviewed by Kelly Kennedy, RDNReviewed: May 5, 2020Medically ReviewedMagnesium is a veritable workhorse among the minerals your body needs. You need it for muscle function, normal heart rhythm, blood glucose control, nerve function, to transport other minerals throughout the body, and for basic energy needs, according to the National Institutes of Health. (1) Here’s what you should know about how much magnesium you need every day, where to get it from, and when you should think about taking magnesium supplements. What Is Magnesium and Why Do I Need It Magnesium is a mineral that is naturally found in plant and animal foods. For humans, it’s an essential nutrient, helping with more than 300 different biochemical reactions that take place in our bodies all the time, the NIH notes. (1) As an ionic or “charged” particle, magnesium is an important electrolyte that supports optimal nerve and muscle function, including involuntary muscles like the heart. It may help lower blood pressure. In fact, one study in July 2016 in the journal Hypertension, found that participants who received additional magnesium through a supplement of about 300 milligrams (mg) per day for three months increased their blood levels of the mineral and reduced their systolic blood pressure (the top reading of a blood pressure reading) by two points and diastolic blood pressure (the bottom number on that reading) by 1.78 points. (2) Magnesium — along with other nutrients like chromium — also helps regulate blood sugar. According to the Linus Pauling Institute at Oregon State University in Corvallis, magnesium intake has been shown to improve insulin sensitivity and may be useful for the prevention and management of type 2 diabetes. (3) The human body needs adequate magnesium to support immunity and turn food into energy. What’s more, magnesium helps the body absorb other essential minerals, including calcium and potassium — meaning it plays a role in all the functions that those minerals support, too (such as maintaining bone health). You may also be surprised to learn that magnesium is the third most prevalent mineral in human bones, after calcium and phosphorus — and 60 percent of the magnesium in the body is stored in the skeleton, according to the NIH. (1) Common Questions & AnswersWhy do I need magnesium?This mineral is a component in enzymes needed for more than 300 reactions in the body. It helps regulate blood pressure, calcium, and blood glucose levels, helps nerve conduction and muscle contraction, and bolsters the immune system. It’s also an integral part of your bones and teeth.What are the symptoms of low magnesium?Hypomagnesemia — low magnesium in the blood — is very rare in the absence of certain medical issues. Mild symptoms include decreased appetite, nausea, vomiting, fatigue, and weakness.What are the risks and benefits of taking a magnesium supplement?Magnesium supplements are generally considered safe, but some people may experience gastrointestinal issues, like diarrhea, cramps, and nausea. Supplements may help with constipation, muscle cramping, and preventing or managing conditions including diabetes, osteoporosis, and heart disease.What foods have magnesium?Foods with magnesium include leafy greens like spinach, nuts and seeds such as almonds and cashews, beans and legumes like black beans, soy in various forms, such as edamame, fatty fish (for example, salmon), whole grains, and certain brands of mineral water.How much magnesium do I need?The recommended amount differs depending on your age and sex. Women ages 19 to 30 should aim for 310 milligrams (mg) per day, then 320 mg a day after age 31. Men 19 to 30 should aim for 400 mg per day, then 420 mg per day after age 31. Pregnant and breast-feeding women will require slightly more. How Much Magnesium Do I Need Recommended dietary allowances (RDAs) are the average daily intake levels (of any given vitamin or mineral) that sufficiently meet the nutrient requirement for most healthy individuals. RDAs for magnesium vary by age and gender, according to the NIH: (1) Recommended Amount for Women Ages 14 to 18 360 mg/dayAges 19 to 30 310 mg/dayWomen 31 and older 320 mg/day Recommended Amount for MenAges 14 to 18 410 mg/dayAges 19 to 30 400 mg/dayAges 31 and older 420 mg/day Recommended Amount for InfantsUp to 6 months old 30 mg/day6 to 12 months 75 mg/day Recommended Amount for ChildrenAges 1 to 3 80 mg/dayAges 4 to 8 130 mg/dayAges 9 to 13 240 mg/day Most Recent in Diet & Nutrition What Happens to Your Cholesterol When You Go on a Keto Diet 10 Mocktail Recipes So Good You Won t Believe They re Booze-Free Do Sports Drinks Count as Fluid See all in Diet & Nutrition Foods High in MagnesiumGenerally speaking, some of the best food sources of magnesium are those that are high in fiber. According to the NIH, they include: (1)Spinach 78 mg per ½ cup boiledCashews 74 mg per 1 ounce (oz) dry roastedBlack beans 60 mg per ½ cup cookedEdamame 50 mg per ½ cooked and shelledSalmon 24 mg per 3 oz cookedPeanut butter 49 mg per 2 tablespoonsWhole-wheat bread 46 mg per 2 slicesSome brands of mineral water (check labels, amounts vary greatly) 1 mg per liter to 120 mg per liter The above list includes good sources not only of magnesium, but also phytonutrients, which are plant chemicals that promote health and immunity. Refining and processing foods depletes naturally occurring magnesium, so as usual, it is best to opt for minimally processed sources. Other foods with magnesium include:YogurtBananasAvocadosPotatoesMilkRaisins Learn More About Foods High in Magnesium Editor s Picks on Vitamins and Minerals 7 Common Nutrient Deficiencies Supplements May Not Offer Same Benefits as Nutrient-Rich Foods What Is IV Nutritional Therapy and Why Are Some Celebrities Crazy for It The 6 Best Nutrient Pairings for Heart Health Signs and Symptoms of Magnesium DeficiencySome of the early symptoms of a deficiency are muscle weakness, fatigue, low appetite, nausea, and vomiting. Because these symptoms may be due to a multitude of other issues, it is advisable to see your physician if you are experiencing them. Blood tests, however, are not a valid measure of overall magnesium stores, since we store most of the mineral in our bones. Some researchers believe many cases of chronic magnesium deficiency go undiagnosed. (1) This type of unrecognized deficiency is problematic because it may contribute to many common medical conditions, including cardiovascular disease, diabetes, and osteoporosis, according to an article published in January 2018 in Open Heart. (4) Risk Factors for Magnesium Deficiency Although Americans generally don’t get optimal amounts of magnesium every day, deficiencies that result in health harms are relatively rare, according to Harvard Health. (5) The following would put you at risk for deficiency, notes the Harvard T.H. Chan School of Public Health: (6)Alcohol abuseAdvanced ageCrohn’s or celiac disease, which can prevent proper nutrient absorption in the bodyDiabetes and taking medication for diabetesCertain medications that deplete magnesium, including some diuretics, proton pump inhibitors, and antibiotics Learn More About Signs and Symptoms of Magnesium Deficiency Potential Health Benefits of Magnesium Not getting enough magnesium can disrupt a lot of bodily processes that happen each day. And new evidence suggests that over time the consequences can add up and may play a role in these chronic problems. Preventing High Blood Pressure Heart Disease and Stroke “Your heart is essentially a large muscle,” says Olivia Wagner, RDN, an integrative registered dietitian nutritionist in Chicago. Magnesium works in tandem with calcium to support blood pressure, and it also may balance lipid levels, all of which helps promote healthy heart function, she says. A study published in January 2016 in the Journal of the American Heart Association found a link between low serum magnesium levels and both coronary heart disease (CHD) and sudden cardiac death, but it remains unclear exactly why the relationship exists or if supplementing with magnesium would lower the risk of either. (7) Several studies have associated healthy levels of magnesium in the diet with a lower incidence of stroke, but because much of the research on both CHD and stroke is from observational studies, this is just an association; more data are needed from randomized clinical trials to determine if higher magnesium levels directly reduce the risk of these conditions, notes a February 2018 review in the journal Nutrients. (8) RELATED: The 6 Best Nutrient Pairings For Your Heart Preventing or Managing Type 2 Diabetes A review of observational research, published in the World Journal of Diabetes in August 2015, on magnesium and type 2 diabetes suggests that adequate magnesium intake may lower the risk of the disease, because people who get adequate magnesium in their diets seem to have lower incidence of this chronic health problem. (9) “If you’ve been diagnosed with insulin resistance or prediabetes, then taking extra magnesium may really help you,” says Robin Foroutan, RDN, who specializes in integrative and functional medicine at the Morrison Center in New York City. Furthermore, if you have diabetes, magnesium supplementation may also help keep you healthy. Having type 2 diabetes raises your risk for heart disease, but people with a higher blood level of magnesium are less likely to develop coronary heart disease, per a March 2018 study in the journal Nutrients. (10) RELATED: What You Need to Know About Magnesium and Type 2 Diabetes Maintaining Bone Health and Preventing Osteoporosis Magnesium is essential for bone formation, says Foroutan. It also indirectly affects bone density because it is part of the system that regulates the important bone nutrients calcium and vitamin D. Thus, it is important to get enough magnesium to support your skeleton. As a study on middle aged and older adults in the November 2017 issue of Nutrients suggests, consuming magnesium-rich foods may play an important role in preventing diseases like osteoporosis and bone fracture. (11) Easing Migraine In the few clinical trials conducted, magnesium helped lower the frequency, duration, and severity of migraine. (12) The therapeutic dose for migraine treatment is well above the recommended maximum from supplements, so it is safest to seek the help of a healthcare professional for advice and monitoring. Still, Foroutan says that for some people with migraine who aren’t actually low in magnesium, megadoses — or excess magnesium — may be helpful in inhibiting attacks. Learn More About the Health Benefits of Magnesium More on Magnesium Benefits How Magnesium Keeps Your Heart Rhythm HealthyLow levels of magnesium are associated with atrial fibrillation, among other heart-related issues.…Learn More Do I Need a Magnesium Supplement You may not need a supplement, and you can optimize your intake through dietary changes, says Wagner. Still, some healthcare professionals believe that much of the public has what’s called “subclinical magnesium deficiency,” which means that a person runs chronically low in the mineral but not low enough to be defined as deficient. According to the aforementioned study in the journal Open Heart, there may be several factors at work in this widespread deficiency, including lack of nutrients in soil and an excess intake of processed foods, which are stripped of minerals. (2) If you’re dealing with certain symptoms that might suggest you’re running low in magnesium — frequent headaches, muscle cramping at night or with exercise, fatigue, or constipation — you may benefit from a magnesium supplement, says Wagner. Talk to a healthcare professional to see what’s right for you. Health Risks From Consuming Too Much Magnesium Overall, magnesium supplements are safe, as long as you’re following the label or a doctor's recommendations and not consuming excessive amounts, says Foroutan. Taking too much will act as a laxative — one clue that you’re going overboard. While your kidneys do flush out excess magnesium (it is a water-soluble mineral), getting too much of the mineral from supplements can cause diarrhea (often accompanied by nausea and abdominal cramping) — and in very large doses can cause more serious problems like retention of urine, difficulty breathing, irregular heartbeat, and cardiac arrest. Those more serious consequences have resulted from magnesium doses exceeding 5,000 mg per day, according to the NIH. (1) People with acid reflux who take proton pump inhibitor medications for more than one year are at risk for low magnesium levels, according to the U.S. Food and Drug Administration. The FDA warns that even magnesium supplements didn't raise levels enough in these people. (13) Because extra magnesium is eliminated by your kidneys, anyone who has renal impairment should not take supplements without discussing it with a healthcare provider. Likewise, anyone taking certain medications, including bisphosphonates, antibiotics, diuretics, or proton pump inhibitors should be aware of possible adverse drug-nutrient interactions. Be sure to speak with your healthcare team before starting this or any other supplement. Most Popular in Diet and Nutrition 10 Healthy Foods That Are Great Sources of Iron A Complete Keto Diet Food List and 7-Day Sample Menu 8 Scientific Health Benefits of the Mediterranean Diet 10 Foods High in Potassium Types of MagnesiumIf you do decide to take a magnesium supplement, you’ll need to decide what type to take. Different types of magnesium vary in price, how well your body can absorb them, and potential side effects. Research suggests that magnesium aspartate, lactate, chloride, and citrate are best absorbed by our bodies. Whereas magnesium oxide and magnesium sulfate (also known as Epsom salt), which can also be taken orally, are less easily absorbed. The types of magnesium most likely to cause diarrhea are magnesium carbonate, chloride, gluconate, and oxide, according to past research. (14) Keep in mind that supplements can be a natural way to relieve constipation due to their laxative effect. Magnesium threonate is a form of magnesium that may pass into the brain more efficiently, thus both Wagner and Foroutan use it when addressing mood, sleep, and cognition issues. Summary Magnesium clearly plays a large role in the healthy function of your body. It’s possible that you are running low on magnesium, especially if you’ve been struggling with insulin levels, muscle cramps, or migraine. Magnesium-rich foods and supplements can safely help get your levels back up so you can feel great. Additional reporting by Jessica Migala. Editorial Sources and Fact-Checking Magnesium. National Institutes of Health. October 2019.Zhang X, Li Y, Del Gobbo LC, et al. Effects of Magnesium Supplementation on Blood Pressure: A Meta-Analysis of Randomized Double-Blind Placebo-Controlled Trials. Hypertension. July 2016.Magnesium. Linus Pauling Institute at Oregon State University.DiNicolantonio JJ, O’Keefe JH, Wilson W. Subclinical Magnesium Deficiency: A Principal Driver of Cardiovascular Disease and Public Health Crisis. Open Heart. January 2018.What You Should Know About Magnesium. Harvard Health Publishing.Magnesium. Harvard T.H. Chan School of Public Health.Kieboom B, Niemeijer MN, Leening M, et al. Serum Magnesium and the Risk of Death From Coronary Heart Disease and Sudden Cardiac Death. Journal of the American Heart Association. January 2016.Rosique-Esteban N, Guasch-Ferre M, Hernandez-Alonso P, et al. Dietary Magnesium and Cardiovascular Disease: A Review With Emphasis in Epidemiological Studies. Nutrients. February 2018.Barbagallo M, Dominguez LJ. Magnesium and Type 2 Diabetes. World Journal of Diabetes. August 2015.Gant CM, Soedamah-Muthu S, Binnenmars SH, et al. Higher Dietary Magnesium Intake and Higher Magnesium Status Are Associated With Lower Prevalence of Coronary Heart Disease in Patients With Type 2 Diabetes. Nutrients. March 2018.Welch AA, Skinner J, Hickson M. Dietary Magnesium May Be Protective for Aging of Bone and Skeletal Muscle in Middle and Younger Older Age Men and Women: Cross-Sectional Findings from the UK Biobank Cohort. Nutrients. November 2017.Volpe S. Magnesium in Disease Prevention and Overall Health. Advances in Nutrition. May 2013.DA Drug Safety Communication: Low Magnesium Levels Can Be Associated With Long-Term Use of Proton Pump Inhibitor Drugs (PPIs). U.S. Food and Drug Administration. March 2, 2011.Ranade V, Somberg J. Bioavailability and Pharmacokinetics of Magnesium After Administration of Magnesium Salts to Humans. 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