11 Subtle Signs of Low Magnesium Experts Say You Should Know

Why is low magnesium so common? Many people simply don’t eat enough vegetables, which are naturally rich in magnesium, explained Erin Barrett, Ph.D., director of product innovation and scientific affairs at Shaklee. Meanwhile, many processed foods are stripped of minerals when they’re refined.

There’s also the fact that some people just need more magnesium than others, added 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, all of whom may have a harder time absorbing magnesium, per the NIH.

Since magnesium deficiency is typically asymptomatic, it can be hard to tell if you’re getting enough of the mineral. However, there are some subtle (and not so subtle) signs that you need more in your diet. Here, experts share the symptoms that may be linked to low magnesium, plus what to do if you suspect that you may need to increase your intake of the mineral.

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 said. “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 described 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), said Barrett. That’s because magnesium regulates calcium and potassium, two electrolytes that affect your muscles and nerves. “When magnesium is low, nerves and muscles become more excitable,” Barrett explained. 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 said.

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 said. 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 explained. 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 explained. 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 said. “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 said. Maybe your mind is racing at night, she said. Or maybe you just don’t feel rested, Barrett added. Either way, low magnesium may be your problem, and more magnesium may improve 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 explained. 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 said. When these processes get thrown off, you might experience mood swings, what Landry called “personality changes,” or even mild depression. “Think of [magnesium] as your body’s chill-out mineral,” Peterson said. “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 said (which is why some people take magnesium citrate for constipation). Since GI woes (and many low magnesium symptoms) can also be signs of other health conditions, look for other symptoms happening simultaneously—like fatigue, muscle cramps, or stress—before assuming magnesium is the culprit. “A red flag combo?” Peterson said. “Constipation and chronic stress.”

Sugar cravings

Suddenly craving sugar? Low magnesium may be behind your sweet tooth, Peterson said. That’s because magnesium helps regulate your blood sugar, and low magnesium can make it harder to keep your blood sugar healthy, Barrett said. Blood sugar imbalances—like hypoglycemia (low blood sugar) or hyperglycemia (high blood sugar)—can make you hungry, according to the American Diabetes Association (ADA), which may lead to more intense cravings for sweets.

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 said. Over time, not getting enough magnesium “may contribute to reduced bone density,” she explained. This can eventually lead to osteoporosis, a condition where your bones become weak, fragile, and easy to break, Davis and Barrett said.

The good news: If you’re experiencing a handful of the above issues and low magnesium is indeed the culprit, eating more magnesium-rich foods, such as pumpkin seeds, almonds, leafy greens, brown rice, and black beans, should quell your symptoms, said Matt Landry, Ph.D., R.D.N., an assistant professor at UC Irvine Joe C. Wen School of Population & Public Health.

Adding a magnesium supplement could also help, though there are many different types of magnesium that may be best for different problems, such as difficulty sleeping or digestive woes. Before starting a magnesium supplement, 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 and a recommendation on the best form for you.

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.