When we don’t feel our best, many of us turn to an examination of our diet to try to pin down exactly what’s wrong. And though it may not always give us the answers to cure what ails us, it’s never a bad idea to check in to see if what we’re eating—or not eating—could be contributing to unpleasant physical symptoms. One nutrient that can become deficient in the American diet, bringing various undesirable consequences, is magnesium.
Who becomes deficient?
While it’s fairly rare for otherwise healthy people to experience extreme symptoms of magnesium deficiency, certain risk factors can make it more likely. People with gastrointestinal disorders, like Crohn’s disease or celiac disease, are especially susceptible because these conditions keep the GI tract from absorbing nutrients like it should—magnesium included. Diabetes, kidney disorders, and chronic alcohol abuse also make it harder for the body to retain a healthy supply of this mineral. And because more magnesium gets excreted in the urine as we age, deficiency becomes more common the older we get (1).
Even if you don’t suffer from any of these risk factors, it’s not impossible for your magnesium levels to get too low simply due to a poor diet. The Standard American Diet (aptly nicknamed SAD) is lacking in many of the foods that supply it. In fact, one study found that nearly half the U.S. population consumed less than the required daily amount of magnesium (2). So whether or not you’re experiencing symptoms related to deficiency, it can’t hurt to consider how much magnesium your diet provides.
Giving it some thought
Because it’s not listed on most nutrition labels, we may not usually give much thought to the amount of magnesium we’re getting. Some have even nicknamed it the “orphan nutrient” because of how little attention it gets in the media and scientific research. Currently, the FDA only requires food manufacturers to list percentages of vitamin A, vitamin C, calcium, and iron each serving of a given food contains (3). So if you ever do see magnesium on the black-and-white box on the side of a packaged food, it’s because the manufacturer has elected to put it there. (Usually, to show off the nutrients their product contains, á la breakfast cereals fortified with tons of extra vitamins.)
So how do you know if your diet is supplying you with the magnesium you need? For reference, the Recommended Daily Intake for magnesium is 400 milligrams for males age 19-30, and 420 after 30, and for women, 310 milligrams for ages 19-30 and 320 beyond age 30 (4). But since it can be tricky to track every last milligram of any nutrient in what we eat, it’s probably more practical to just strive to include magnesium-rich foods in your diet regularly.
High Magnesium Foods
The great news about getting more magnesium is that you don’t have to load up on anything weird or obscure to do so. Many high-magnesium foods are ones you’re probably eating (and enjoying) already. Here are a few examples.
Nuts, seeds, and legumes
A quarter cup of almonds contains 76 milligrams of magnesium (about 20% of your daily recommendation). Cashews and Brazil nuts are also good sources. In the same family as nuts and seeds, legumes follow suit with plenty of magnesium. Lentils, beans, and peas can take care of your day’s needs to the tune of 120 milligrams in cooked black beans.
One tablespoon of sesame seeds contains 32 mg of magnesium, or 10% of your daily value. So while you may not be able to get your entire day’s supply from your Chinese takeout, it certainly adds to the big picture of your intake.
Whole wheat and other grains
Want to knock out half your day’s magnesium needs with a single food? Look no further than whole wheat flour, with 160 milligrams per cup. And don’t forget other grains, too! One cup of cooked quinoa contains a whopping 118 milligrams of magnesium.
Leafy greens are among the healthiest veggies on the planet, in part because they’re loaded with magnesium. Spinach, kale, collard greens, and mustard greens all boast significant amounts, up to about 40% of your recommended daily intake in one cup. Pass the salad!
Avocados aren’t just trendy—they’re good for you. In addition to their fiber and much-touted healthy fats, avocados contain plenty of magnesium, about 60 milligrams in one medium avocado. Spread some on toast, chop some for a burrito, or add some to a burger.
Chocolate lovers, rejoice! Dark chocolate is an excellent source of magnesium. One ounce of the sweet stuff packs 64 milligrams, providing around 15% of your daily recommendation. Pair dark chocolate chips with whole wheat in cookies for a magnesium-rich dessert. (See, we knew cookies were good for us.)
Signs of Magnesium Deficiency
Because magnesium helps the body perform many of its critical functions—like muscle relaxation, energy transport, and nerve signaling—when we don’t get enough, serious problems can result (1). Whether due to chronically low levels of intake in food or any of the risk factors described above, deficiency doesn’t usually happen overnight. Typically, symptoms begin vaguely and progress to the more dramatic as time goes by. Here’s what to watch out for.
As a mystery symptom, fatigue is among the most common. So don’t jump to the conclusion that a feeling of sluggishness is due to low magnesium—but it is a possibility, as fatigue can be one of the first symptoms to show up when magnesium gets low (4).
Appetite loss, nausea, and vomiting
Early symptom of insufficient magnesium can also include GI issues. Nausea, vomiting, and loss of appetite are not uncommon (4).
Muscle cramps and twitches
Could an annoying eyelid twitch be related to low magnesium? Since this mineral aids muscle relaxation, when there’s not enough of it to go around, muscle twitches and cramps can result. Over time, dangerously low magnesium can even lead to seizures or convulsions (5).
Another way muscles can be affected by magnesium levels is to become weaker. Magnesium needs to coexist in a delicate balance with other minerals in the body for muscles to do the work of contracting (6).
If your heartbeat sounds less like a steady drum and more like a jam session, magnesium could be at play. Low levels can make it difficult for the heart to contract and relax in its usual, rhythmic manner (7).
High blood pressure
When certain things go too low in the body, others go too high. Several studies have linked low magnesium to high blood pressure (1).
Constipation, headaches, hormonal issues, anxiety, insomnia, difficulty with stress.
How to know if you’re deficient
If you suspect you’ve become deficient in magnesium, talk to your doctor. A blood test is the only way to determine for certain if your levels are low. In addition to upping your intake of high-magnesium foods, your healthcare professional may also recommend a supplement, especially if you have a condition that inhibits your body’s ability to absorb this nutrient. Some evidence indicates that pairing magnesium with other minerals (as in magnesium citrate or magnesium chloride) helps with absorption—but follow your doctor’s instructions regarding product selection and dosage (4). Also, be aware that taking magnesium can have its own (possibly unpleasant) symptoms, like diarrhea.
Can I get too much?
It’s hard to get too much magnesium in your diet, so don’t be afraid to load up on magnesium-rich foods. You won’t become magnetic or sprout silver crystals out your ears. Supplemental magnesium, though, can cause problems when taken to excess. In addition to giving some people diarrhea, too much OTC magnesium can be dangerous for people with health conditions like kidney disease (8). Again, talk to your doctor before starting any dietary supplement.
When you dig in to the science, it’s clear that the body maintains an amazingly delicate balance of vitamins and minerals. With our food and lifestyle choices, we can keep a good thing going. As you follow your own path of healthy eating and healthy living, don’t forget magnesium!
- https://lpi.oregonstate.edu/mic/minerals/magnesium – reference2