Experts call magnesium a “hidden hero” of nutrition, thanks to its many health benefits. The mineral helps your body produce energy, regulates blood sugar and blood pressure, and supports your nerves and muscles—including your heart, per the National Institutes of Health (NIH). Knowing magnesium deficiency symptoms can help you identify if you’re lacking in the mineral.
“Magnesium is one of those under-the-radar minerals that quietly powers hundreds of essential processes in the body,” says Samantha Peterson, R.D., founder and CEO of Simply Wellness.
While magnesium deficiency is rare, research consistently shows that 48% of Americans get less magnesium than they should, per the NIH. That’s because many of us don’t eat enough vegetables, which are naturally rich in magnesium, explains Erin Barrett, Ph.D., director of product innovation and scientific affairs at Shaklee. And many processed foods are stripped of minerals when they’re refined.
Plus, some people just need more magnesium than others, adds Amy Davis, R.D.N., Live Conscious nutrition consultant. These include older adults, people with certain health conditions (like gastrointestinal conditions, type 2 diabetes, and substance use disorders), and people on certain medications—who may all have a harder time absorbing magnesium, per the NIH.
Meet the experts: Samantha Peterson, R.D., founder and CEO of Simply Wellness; Erin Barrett, Ph.D., director of product innovation and scientific affairs at Shaklee; Amy Davis, R.D.N., Live Conscious nutrition consultant; Matt Landry, Ph.D., R.D.N., assistant professor at UC Irvine Joe C. Wen School of Population & Public Health.
Since magnesium deficiency is rarely symptomatic, it can be hard to tell if you’re getting enough of the mineral. But, there are some subtle (and not so subtle) signs that you need more in your diet, according to experts.
Fatigue
If you’re feeling tired, weak, or generally low on energy, your magnesium levels may be to blame. “Magnesium is essential for making ATP—the main energy molecule in your cells,” Barrett says. “Without enough of it, your body can’t produce or use energy efficiently, which can leave you feeling tired or weak.” This is one of the most common signs of low magnesium. And if you’re struggling to tell the difference between run-of-the-mill fatigue and true exhaustion, keep an eye out for “persistent fatigue that doesn’t improve with rest,” as Landry describes it.
Muscle cramps and spasms
Low magnesium can make your muscles cramp, twitch, spasm, and tingle—and in some cases, it may even cause seizures or repetitive eye movements (nystagmus), says Barrett. That’s because it regulates calcium and potassium, two nutrients that affect your muscles and nerves. “When magnesium is low, nerves and muscles become more excitable,” Barrett explains. That can cause your muscles to feel weaker, twitchier, or just different than usual. Think: “Waking with tight calves” or “having muscle cramps at night,” Peterson says.
Anxiety or irritability
Feeling stressed, anxious, or irritable for no apparent reason? Check your magnesium levels. “Magnesium is a key player in calming the nervous system,” Peterson says. It helps regulate your neurotransmitters, including feel-good chemicals like dopamine and serotonin, and fight-or-flight hormones like epinephrine. “When [magnesium is] low, the brain and muscles can go into overdrive, making you feel on-edge, tense, or mentally revved up,” she explains. This can leave you with unexplained stress or anxiety—or simply make you more irritable than usual.
Irregular heartbeat
Any time you notice your heart racing or beating irregularly, you should tell your doctor. But in some cases, low magnesium may be the reason, per Barrett, Davis, and Landry. “Magnesium plays a role in stabilizing electrical activity in the heart,” Davis says. So low levels of the mineral can throw things off, making your heart rate fast or irregular.
Headaches
One lesser-known symptom of low magnesium? Headaches or migraines, especially if you start experiencing them more frequently. “Magnesium influences nerve transmission and blood vessel function in the brain,” Barrett says. “Deficiency has been linked to an increased risk of migraines in some people.” Though this low magnesium symptom won’t impact everyone, all four experts recommend keeping an eye out for it.
Trouble sleeping
Low magnesium can make you feel tired, even when you’re getting enough sleep. But it can also impact your ability to fall asleep and stay asleep through the night. “If someone is feeling ‘wired but tired’ … or having trouble falling asleep despite being exhausted, I often take a closer look at magnesium,” Peterson says. Maybe your mind is racing at night, she says. Or maybe you just don’t feel rested, Barrett adds. Either way, low magnesium may be your problem, and more magnesium might help you sleep. But again, be sure to consult your doctor before adding anything to your routine.
High blood pressure
Since magnesium helps regulate blood pressure, not getting enough of the mineral may increase your risk of high blood pressure, per Barrett and Davis. “Magnesium helps relax blood vessel walls, supporting healthy circulation and normal blood pressure levels,” Barrett explains. And research suggests that upping your intake (through magnesium supplements or your diet) may lower your blood pressure and reduce your risk of heart disease or stroke, per the NIH.
Mood swings
Low magnesium levels can leave you feeling moody, depressed, or unlike yourself, according to Davis and Landry. “Magnesium helps regulate [your] neurotransmitters and stress response,” Davis says. When these get thrown off, you might experience mood swings, what Landry calls “personality changes,” or even mild depression. “Think of [magnesium] as your body’s chill-out mineral,” Peterson says. “Without it, things start to misfire.”
Digestion issues
In some cases, low magnesium can impact your digestive system, causing symptoms like constipation and abnormal stools, Peterson says. Since these (and many low magnesium symptoms) can also be signs of other health conditions, look for other symptoms—like fatigue, muscle cramps, or stress—before assuming magnesium’s the culprit. “A red flag combo?” Peterson says. “Constipation and chronic stress.”
Sugar cravings
Suddenly craving sugar? Low magnesium may be behind your sweet tooth, Peterson says. That’s because magnesium helps regulate your blood sugar, and low magnesium can make it harder to keep your blood sugar healthy, Barrett says. Blood sugar imbalances—like hypoglycemia (low blood sugar) or hyperglycemia (high blood sugar)—can make you hungry, according to the American Diabetes Association (ADA).
Weak bones
Magnesium helps your body build healthy bones. “[It] supports bone structure and helps regulate calcium and vitamin D—two nutrients essential for strong bones,” Barrett says. Over time, not getting enough magnesium “may contribute to reduced bone density,” she explains. This can eventually lead to osteoporosis, a condition where your bones become weak, fragile, and easy to break, Davis and Barrett say.
The bottom line
The good news? If low magnesium is indeed the culprit, eating more magnesium-rich foods should quell your symptoms, says Matt Landry, Ph.D., R.D.N., assistant professor at UC Irvine Joe C. Wen School of Population & Public Health. Or adding magnesium supplements could help. Be sure to discuss your concerns with your doctor; they can do a blood test to see if your levels are low and provide you with a tailored plan.
Dietary supplements are products intended to supplement the diet. They are not medicines and are not intended to treat, diagnose, mitigate, prevent, or cure diseases. Be cautious about taking dietary supplements if you are pregnant or nursing. Also, be careful about giving supplements to a child, unless recommended by their healthcare provider.
