The various nutrients we get from food give us the energy we need to move through the day, keep our bones and teeth strong, protect us from a host of diseases, and so much more. Unfortunately, though, many of us fall short on at least one of these ever-important nutrients: magnesium.
As many as 50 percent of Americans don’t get enough of magnesium, according to the American Osteopathic Association. And here’s the thing—that number might actually be even higher based on recent research. Here’s why this mineral is so important, what red flags indicate you’re not getting enough of it, and how to increase your intake.
Why Magnesium Matters
“Magnesium is a mineral found in our skeleton, muscles, soft tissues, cells, blood, and extracellular fluids,” explains The Vitamin Shoppe nutritionist Brittany Michels, R.D.N. “It’s needed in over 350 processes in the body, including nerve function, blood pressure and blood sugar management, energy metabolism, immune support, cardiovascular health, bone health, and protein synthesis, to name just a few.”
Think of magnesium as your body’s multi-tasking mineral. It’s literally involved in hundreds of little jobs happening inside you right now:
- Helping your heart beat steadily
- Allowing your muscles to relax after they contract
- Supporting nerve function throughout your body
- Managing blood pressure and blood sugar levels
- Contributing to energy metabolism
- Maintaining bone health and protein synthesis
When you don’t have enough, it’s like trying to run a busy office with half the staff missing. Things start to slip.
Why Low Magnesium Is Hard to Detect
What makes magnesium especially tricky is that your body stores most of it in your bones and muscles, with less than one percent floating around in your bloodstream. That means a standard blood test might not catch a deficiency until things get pretty serious. Your body is really good at keeping blood levels normal by pulling from its reserves, even when those reserves are running dangerously low.
Signs You’re Not Getting Enough Magnesium
Since the body can’t produce magnesium on its own, we must get it from foods (think spinach, cashews, almonds, and dark chocolate), says The Vitamin Shoppe nutritionist Karen Cooney, M.A., C.N., C.H.H.C.
When we fall short, our health is impacted in multiple ways, but many of these symptoms are easy to brush off or blame on other things:
- Stress
- Aging
- Not sleeping well
- Being “out of shape”
When several of these signs show up together, magnesium deficiency might be the common thread tying them all together. Here are seven signs your body needs more magnesium.
1. You experience muscle cramps or restlessness
Both full-on muscle cramps and general muscle restlessness (think jumpy legs at night when you’re in bed) are tell-tale signs of low magnesium levels. “If your muscles won’t settle down after a long, sweat-drenched workout, you’ve most likely lost too much magnesium via your sweat,” says Michels. Fail to replace it and your muscles pay the price.
What’s Happening Inside Your Muscles
Here’s what’s happening: Magnesium acts like a natural muscle relaxer by controlling how calcium moves in and out of your muscle cells. When magnesium is low, calcium floods into the cells unchecked, causing them to stay contracted. It’s like your muscles get stuck in the “on” position and can’t fully relax.
You might notice this most at night:
- Annoying calf cramps that wake you up
- Legs that just won’t stop twitching when you’re trying to fall asleep
- Persistent charley horses despite stretching and staying hydrated
Athletes and people who exercise regularly are especially prone to this since you lose magnesium through sweat. If you’ve ever wondered why that charley horse keeps coming back despite stretching and staying hydrated, magnesium might be the missing piece.
2. You have trouble sleeping
If you have a hard time falling and staying asleep, being low on magnesium could be behind it, notes Erin Palinski-Wade, R.D., C.D.E., dietitian and author of Belly Fat Diet for Dummies. “Magnesium is a natural relaxant in the body that helps to deactivate the stress hormone adrenaline, which acts as a stimulant and can keep you awake,” she explains. “It has been found that diets lacking in the mineral are associated with difficulty falling asleep and staying asleep, so adding more of it to your diet can play a large role in improving sleep.”
How Magnesium Supports Sleep
What’s more, magnesium helps regulate melatonin (your body’s sleep hormone) and supports your natural sleep-wake cycle. When you’re running low, it’s like your body’s internal clock gets a bit out of sync. You might find yourself wide awake at 2 a.m., mind racing, unable to shut down even though you’re exhausted.
Many people notice that taking magnesium in the evening helps them relax and drift off more easily. It’s not a sedative—it won’t knock you out—but it helps your nervous system calm down naturally, making it easier for sleep to come. If you’re someone who lies in bed with racing thoughts or physical restlessness, this mineral might help bring that much-needed calm.
Read More: This Morning Routine Will Help You Sleep Better At Night
3. You feel fatigued all day
According to Cooney, chronic fatigue is one of the most common symptoms of magnesium insufficiency. “Low levels affect the production of energy, as well as the muscles and nerves,” she explains. Even though you might think muscle contractions only matter during your workouts, poor muscle function also means you may feel tired just walking up the stairs, too.
The Energy Connection
Here’s the science made simple: Your cells produce energy in the form of ATP (think of it as your body’s energy currency), and magnesium is absolutely essential for creating ATP. Without enough magnesium, your cells simply can’t make energy efficiently. It’s like trying to charge your phone with a damaged cable—the power’s there, but it’s not getting through properly.
This isn’t the kind of tiredness that improves after a good night’s sleep or a cup of coffee. It’s a deep, persistent exhaustion that makes even simple tasks feel overwhelming. You might notice:
- You’re dragging by mid-afternoon
- Exercise that used to feel manageable now leaves you completely wiped out
- Even simple tasks feel overwhelming
If you’ve been to the doctor and ruled out other causes of fatigue (like thyroid issues or anemia) but still can’t shake that tired feeling, magnesium levels are worth considering.
4. You’re stressed all the time
Stress can be caused by myriad factors, including everything from your job or social life, to mental health conditions, to chronic illnesses or injury. That said, feeling anxious or having trouble managing stress are also potential signs of low magnesium levels, notes Michels. “During times of unmanaged stress and chronically elevated levels of cortisol (the stress hormone), magnesium can not help lower cortisol levels and boost the production of GABA, a neurotransmitter that signals relaxation and rejuvenation,” she says. Through both of these functions, the mineral can help you feel more at ease.
The Stress-Magnesium Cycle
Here’s the frustrating cycle: Stress depletes your magnesium stores, and low magnesium makes you more sensitive to stress. It’s like a downward spiral that can be hard to break. When you’re stressed, your body excretes more magnesium through urine, which then leaves you with even less of this calming mineral to help you cope.
You might notice:
- You’re more irritable than usual, snapping at small things that wouldn’t normally bother you
- You feel constantly on edge, like you can’t quite relax even during downtime
- You feel “wired but tired”—your mind is racing but your body is exhausted
GABA, which magnesium helps produce, is basically your brain’s chill-out chemical, so when magnesium is low, your nervous system has a harder time downshifting into relaxation mode.
5. You’re constipated
Chronic constipation is another not-so-fun situation that can occur for a number of reasons—one of which is a low intake of magnesium. “Magnesium can help pull water into the intestines, which then helps to ease constipation,” explains Palinski-Wade. “Since many mag-rich foods also contain fiber, which also helps reduce constipation, adding more from whole-food sources can be especially beneficial.” (Pumpkin seeds, chia seeds, black beans, and edamame all offer a solid dose of magnesium and fiber.)
How Magnesium Aids Digestion
What’s happening in your digestive system is pretty straightforward: Magnesium acts like a gentle muscle relaxer for your intestinal walls while also drawing water into your bowels. Both of these actions help things move along smoothly. When magnesium is low, your intestines can get a bit sluggish and stool becomes harder and more difficult to pass.
This is actually why some forms of magnesium—like magnesium citrate—are sometimes recommended specifically for constipation relief. The effect is usually gentler than harsh laxatives, working with your body’s natural processes rather than forcing things. If you’re someone who needs to plan their entire day around bathroom access or finds yourself uncomfortable and bloated regularly, magnesium might offer some relief. Just start with smaller amounts and increase gradually to avoid the opposite problem!
Read More: 9 Natural Ways To Unclog Your Pipes
6. You experience tingling or numbness
A more serious sign that’s typically associated with severely low magnesium in the body is numbness in the face, feet, fingers, or toes, notes Cooney. “Numbness occurs when electrical impulses traveling through nerves do not get to their destination, which leads to nervous system dysfunction that can cause numbness or tingling in these areas,” she says. (One of the mineral’s many roles in the body is to support these nerve signals!)
Understanding Nerve Signals
Think of your nervous system like an electrical grid—magnesium helps keep the signals flowing smoothly from point A to point B. When levels get really low, those signals can misfire or not transmit properly at all, creating those weird tingling sensations that feel like pins and needles, or areas that go partially numb.
This symptom usually shows up when deficiency has become more severe, so it’s definitely one you don’t want to ignore. Some people describe it as their hands or feet “falling asleep” even when there’s no pressure on them. Others notice an uncomfortable buzzing or prickling sensation. If you’re experiencing this kind of nerve-related symptom, it’s important to talk with your healthcare provider to rule out other causes and get your magnesium levels checked.
7. You notice an irregular heartbeat
Another more advanced and serious sign of extremely low magnesium is an irregular heartbeat or heart arrhythmia. “Low magnesium leads to low potassium levels, which then affect normal heart rhythm and cause missed heartbeats or heart palpitations and/or chest pain,” says Cooney. (These may be accompanied by light-headedness and fainting.) “Arrhythmias are usually mild, however, if they go untreated, they may lead to heart failure or stroke.” In this dangerous case, magnesium injections are often used by healthcare providers to get levels to a safer place, Cooney adds.
How Magnesium Affects Your Heart
Your heart is essentially a muscle that depends on precise electrical signals to beat in a steady rhythm. Magnesium plays a critical role in maintaining that electrical balance, working closely with other minerals like potassium and calcium. When magnesium drops too low, that delicate balance gets disrupted.
You might feel your heart skip a beat, flutter, or race for no apparent reason. Some people describe it as feeling like their heart is “doing flip-flops” in their chest. Others notice a pounding sensation or feel like their heart is beating too hard, even when they’re resting. This is definitely not something to self-diagnose or brush off—if you’re experiencing heart-related symptoms, get medical attention right away. While magnesium deficiency might be a contributing factor, heart symptoms always warrant professional evaluation to rule out more serious cardiac issues.
How to get more magnesium
If you’re experiencing any of the more severe symptoms of low magnesium, call your doctor to identify the root cause and get some professional guidance on how to ease the issues and restore balance in your body.
Otherwise, working with a dietitian (The Vitamin Shoppe’s nutritionists offer free consultations), can help you incorporate more of the mineral into your diet in order to meet your needs.
Food Sources of Magnesium
The best sources of magnesium are rich food sources like:
- Leafy green vegetables – spinach, kale, and Swiss chard
- Nuts and seeds – almonds, cashews, pumpkin seeds, and yes, peanut butter included!
- Legumes – black beans, edamame, and other beans
- Whole grains – brown rice, quinoa, and whole wheat
- Dark chocolate – just one more reason to enjoy a square or two after dinner
- Other sources – avocados, bananas, and fatty fish like salmon also pack in decent amounts
The advantage of food sources is that they come bundled with other beneficial nutrients, and it’s nearly impossible to get too much magnesium from food alone since your body regulates absorption.
Modern soil depletion is another factor that’s making it harder to get enough magnesium from food alone. Even if you’re eating spinach and almonds regularly, those foods may contain less magnesium than they did a few decades ago due to intensive farming practices. This doesn’t mean food isn’t still your best first step, but it does help explain why supplementation has become more common even among people with seemingly healthy diets.
When to Consider Supplements
A magnesium supplement can also come in handy—especially if you:
- Have allergies to any magnesium-containing foods
- Have a health condition that can impact your ability to absorb the mineral, such as Crohn’s disease or celiac disease
- Take certain medications (like diuretics) that can increase magnesium losses
People on prescription drugs should talk to their physician or dietitian about supplements.
Dosage and Forms
While too much magnesium from food isn’t a concern, you can definitely go overboard in the supplement department. “High doses from supplements can cause nausea, abdominal cramping, and diarrhea,” according to Cooney.
Recommended daily intake:
- Men: 400 to 420 milligrams per day
- Women: 310 to 320 milligrams per day
- Upper limit for supplements specifically: 350 mg per day (separate from what you get from food)
Cooney also recommends taking your magnesium in the form of magnesium glycinate, which tends to be easier on the stomach. Other well-absorbed forms include:
- Magnesium citrate – can also help with constipation
- Magnesium malate – well-absorbed and gentle
You might see magnesium oxide in stores because it’s cheaper, but your body doesn’t absorb it nearly as well, so you get less benefit for your money.
Read More: Your Guide To All Of The Different Magnesium Supplements Out There
Special Considerations for Athletes
If you’re an athlete, Michels also recommends adding ZMA to your nighttime regimen. This combination provides:
- Magnesium for muscle function
- Zinc (needed for cellular growth and tissue repair)
- L-theanine (an amino acid that promotes calm)
Together, these support healthy magnesium levels, recovery, and quality rest.
Timing and Tips
One more tip: Timing can matter. Many people find that taking magnesium in the evening works best since it can have a calming, relaxing effect that supports better sleep. Just take it with a bit of food if you notice any stomach sensitivity. And be patient—it might take a few weeks of consistent supplementation to really notice the benefits. Your body needs time to rebuild those depleted stores.
Remember, if you’re working with a healthcare provider on managing specific health conditions or taking medications, always loop them in before starting any new supplement. They can help you determine the right type and dose for your individual needs, and make sure there aren’t any interactions with your medications to worry about.