Magnesium has become increasingly popular in the wellness world — and for good reason.
The mineral is involved in hundreds (yes, hundreds) of enzymatic reactions in the body, making it a key player in carrying out critical functions like blood sugar control and muscle and nerve function, among others.
Despite how important magnesium is, it's considered one of the shortfall nutrients, meaning that many U.S. adults don't consume enough of it, per the 2015-2020 Dietary Guidelines for Americans. In other words, most of us would do well to up our magnesium intake from healthy whole foods.
Below, we explain the health benefits magnesium brings to the table, where we can find the mineral in food and what happens if we get too much or too little of it.
What Is Magnesium?
Magnesium is one of the most commonly occurring minerals in our bodies, so it's not surprising that it plays many critical roles.
"It's also essential for keeping the heart healthy, as it's needed for muscle contraction and relaxation."
Though the mineral is involved in the chemical pathways that produce energy in the body, it's also known to bring calm.
"Magnesium is necessary for activating ATP (or adenosine triphosphate), which is the main source of energy in the body," Largeman-Roth notes. "It's also involved in the sleep-wake cycle."
Is Your Diet Missing Certain Nutrients?
Though the standard American diet tends to be short on magnesium, the mineral actually isn't hard to come by; it's pretty easy to put magnesium-rich foods on your plate (after all, avocado is one of them).
Also nice: Most foods that contain magnesium are great sources of other important nutrients, like gut-friendly fiber and plant-based protein.
How Much Magnesium Per Day You Need
Here's how much magnesium you should get daily, per the National Institutes of Health (NIH).
Average Daily Recommended Amounts
0 to 6 months
7 to 12 months
1 to 3 years
4 to 8 years
9 to 13 years
14 to 18 years
19 to 30 years
31 to 50 years
You can get this mineral from a variety of plant foods. Top food sources of magnesium, per the NIH, include:
- Almonds: 80 mg, 19% DV in 1 ounce
- Spinach: 78 mg, 19% DV in ½ cup (boiled)
- Cashews: 74 mg, 18% DV in 1 ounce
- Soy milk: 61 mg, 15% DV in 1 cup
- Black beans: 60 mg, 14% DV in ½ cup (cooked)
- Edamame: 50 mg, 12% DV in ½ cup (cooked)
- Peanut butter: 49 mg, 12% DV in 2 tablespoons
- Baked potato with skin: 43 mg, 10% DV
Other foods with magnesium include brown rice, oatmeal, bananas, certain fish and avocado.
For something more substantial, try these breakfast nachos that are made with magnesium-rich black beans.
The Benefits of Magnesium
1. It Helps Keep Bones Strong
About 50 to 60 percent of the magnesium in the body is stored in the bones. Much like calcium, magnesium helps maintain bone mineral density, bolstering the bones' structure and strength, per the NIH.
It's not all that surprising, then, that magnesium deficiency has been linked to a greater risk of osteoporosis, according to the Memorial Sloan Kettering Cancer Center.
2. It Helps Promote Healthy Blood Pressure
What's more, research suggests magnesium supplementation may be a beneficial intervention for those with high blood pressure.
Some clinical trials have shown a negative correlation between serum magnesium levels and diastolic BP, per an August 2016 meta-analysis in the journal Hypertension. The researchers conclude that magnesium supplementation can help lower blood pressure.
Magnesium plays a role in reactions in the body that regulate insulin secretion and sensitivity and, in turn, affect blood sugar balance.
Additionally, higher dietary magnesium intake has been associated with a lower risk of type 2 diabetes and 25 to 38 percent of individuals with type 2 diabetes have been shown to possess hypomagnesemia, or low magnesium levels in the blood, per a September 2013 PLOS One study.
As such, it's been theorized that adequate magnesium levels may help prevent against or control type 2 diabetes by decreasing blood sugar levels, however more research is needed to confirm this.
What You Need to Know About Magnesium Deficiency
Low magnesium levels may increase one's risk of a variety of conditions, including migraines, type 2 diabetes, cardiovascular disease and Alzheimer's disease, among others, according to a September 2015 review in the journal Nutrients.
Here's why that's problematic: "The National Health and Nutrition Examination Survey found that nearly 45 percent of Americans don't get enough magnesium in their diets," Largeman-Roth tells LIVESTRONG.com.
That means nearly half the population is missing out on the critical nutrient — and potentially upping their risk of chronic disease as a result (though additional factors are also likely to be at play here).
Magnesium deficiency, according to the NIH, may lead to:
- High blood pressure
- Decreased insulin sensitivity and glycemic control
- Loss of appetite
- Muscle cramps
- Heart rhythm abnormalities
- Additional electrolyte disruptions (low calcium, low potassium)
OK, so who's most at risk of magnesium deficiency?
"Since the mineral is mostly found in whole grains, beans, nuts and seeds, people who don't have a well-rounded diet may not be getting enough magnesium," says Largeman-Roth.
"Individuals with alcoholism, diabetes, GI conditions or who take multiple medications may also be at risk for a deficiency."
Older adults in general are at increased risk for a magnesium deficiency because they don't absorb the mineral as well as younger adults and also tend to excrete more of it by way of the kidneys, per the NIH.
What Happens if You Get Too Much Magnesium?
"In healthy people, there is no risk of taking in too much magnesium from food because any excess is excreted by our kidneys through the urine," says Largeman-Roth.
"However, high doses of magnesium from supplements or medications (like laxatives) can cause diarrhea."
For adults 19 years and older, the tolerable upper intake level (UL) for supplemental magnesium is 350 milligrams per day (so be sure your supplement doesn't contain more than this, if you're taking one).
Health risks associated with consuming more than the UL for magnesium include:
- Abdominal cramping
- Hypotension, or low blood pressure
- Muscle weakness
- Breathing difficulties
- Irregular heartbeat
- Cardiac arrest
Magnesium Drug Interactions and Risks
Magnesium supplements have been shown to interact with common medications, including bisphosphonates for osteoporosis treatment, antibiotics like tetracyclines and quinolones, loop and thiazide diuretics and proton pump inhibitors such as Nexium, among others, per the NIH.
Sulfonylureas for diabetes may also react with magnesium, according to an April 2016 study in Therapeutic Advances in Endocrinology and Metabolism.
Bisphosphonates and antibiotics should be taken at least two hours apart from magnesium supplements to prevent the mineral from reducing their absorption and subsequent activity.
Loop and thiazide diuretics as well as PPIs can promote magnesium excretion, potentially resulting in hypomagnesemia.
Potassium-sparing diuretics like Aldactone, on the other hand, can drive down magnesium removal from the body and thus promote high magnesium levels in the blood.
In general, it's important for healthcare providers to monitor the magnesium status of individuals taking any of the above medications.
What to Look For in a Magnesium Supplement
"Any supplement should be easy to take and well tolerated, meaning it doesn't upset your stomach," says Largeman-Roth.
And it's always important to choose supplements that are made by reputable brands. Bonus points if they're third-party tested and follow the FDA's Current Good Manufacturing Practices.
When it comes magnesium supplements, there are various forms available on the market. Magnesium citrate, for example, is the form most often recommended for managing constipation, according to Michigan Medicine.
Magnesium oxide, on the other hand, is often touted for its ability to relieve symptoms of indigestion, like heartburn, per the U.S. National Library of Medicine.
Talk to your doctor or a registered dietitian before adding a magnesium supplement to your daily routine. Consuming a magnesium supplement without a noted deficiency may lead to adverse symptoms associated with excessive intake.
Below, find the best magnesium supplements according to Consumer Lab's testing.
Best Magnesium Supplements
- 2015-2020 Dietary Guidelines for Americans: "Underconsumed Nutrients and Nutrients of Public Health Concern"
- Hypertension: "Effects of Magnesium Supplementation on Blood Pressure: A Meta-Analysis of Randomized Double-Blind Placebo-Controlled Trials"
- National Institutes of Health: Magnesium Fact Sheet for Health Professionals"
- Memorial Sloan Kettering Cancer Center: "
- Harvard Medical School: "Key Minerals to Help Control Blood Pressure"
- Plos One: "The Relationship Between Hypomagnesemia, Metformin Therapy and Cardiovascular Disease Complicating Type 2 Diabetes: The Fremantle Diabetes Study"
- Nutrients: "Magnesium in Prevention and Therapy"
- Cleveland Clinic: "Heart Block"
- Therapeutic Advances in Endocrinology and Metabolism: "Clinically and Pharmacologically Relevant Interactions of Antidiabetic Drugs"
- Michigan Medicine: "Magnesium Citrate"
- U.S. National Library of Medicine: "Magnesium Oxide"
- Consumer Lab: "Magnesium Supplements Review"