Magnesium is the fourth most abundant mineral in your body.

It’s involved in over 600 cellular reactions, from making DNA to helping your muscles contract ().

Despite its importance, up to 68% of American adults don’t meet the recommended daily intake ().

Low magnesium levels have been linked to many negative health outcomes, including weakness, depression, high blood pressure and heart disease.

This article explains what magnesium does for your body, its health benefits, how to increase your intake and the consequences of getting too little.

What Does Magnesium Do?

Magnesium plays an important role in relaying signals between your brain and body.

It acts as the gatekeeper for the N-methyl-D-aspartate (NMDA) receptors, which are found on your nerve cells and aid brain development, memory and learning ().

In healthy adults, magnesium sits inside the NMDA receptors, preventing them from being triggered by weak signals that may stimulate your nerve cells unnecessarily.

When your magnesium levels are low, fewer NMDA receptors are blocked. This means they are prone to being stimulated more often than necessary.

This kind of overstimulation can kill nerve cells and may cause brain damage ().

Summary Magnesium acts as the gatekeeper for NMDA receptors, which are involved in healthy brain development, memory and learning. It prevents nerve cells from being overstimulated, which can kill them and may cause brain damage.

Magnesium is important for maintaining a healthy heartbeat.

It naturally competes with calcium, which is essential for generating heart contractions.

When calcium enters your heart muscle cells, it stimulates the muscle fibers to contract. Magnesium counters this effect, helping these cells relax (, ).

This movement of calcium and magnesium across your heart cells maintains a healthy heartbeat.

When your magnesium levels are low, calcium may overstimulate your heart muscle cells. One common symptom of this is a rapid and/or irregular heartbeat, which may be life-threatening ().

What’s more, the sodium-potassium pump, an enzyme that generates electrical impulses, requires magnesium for proper function. Certain electrical impulses can affect your heartbeat ().

Summary Magnesium helps your heart muscle cells relax by countering calcium, which stimulates contractions. These minerals compete with each other to ensure heart cells contract and relax properly.

Magnesium also plays a role in regulating muscle contractions.

Just like in the heart, magnesium acts as a natural calcium blocker to help muscles relax.

In your muscles, calcium binds to proteins such as troponin C and myosin. This process changes the shape of these proteins, which generates a contraction ().

Magnesium competes with calcium for these same binding spots to help relax your muscles.

If your body doesn’t have enough magnesium to compete with calcium, your muscles may contract too much, causing cramps or spasms.

For this reason, magnesium is commonly recommended to treat muscle cramps ().

However, studies show mixed results regarding magnesium’s ability to relieve cramps — some even finding no benefit at all ().

Summary Magnesium acts as a natural calcium blocker, helping your muscle cells relax after contracting. When magnesium levels are low, your muscles may contract too much and cause symptoms such as cramps or muscle spasms.

A diet rich in magnesium has been linked to many other impressive health benefits.

May Lower Blood Pressure

High blood pressure is a health concern that affects one in three Americans ().

Interestingly, studies have shown that taking magnesium may lower your blood pressure (, ).

In one study, people who took 450 mg of magnesium daily experienced a fall in the systolic (upper) and diastolic (lower) blood pressure values by 20.4 and 8.7, respectively ().

An analysis of 34 studies found that a median dose of 368 mg of magnesium significantly reduced both systolic and diastolic blood pressure values in both healthy adults and those with high blood pressure ().

However, the impact was significantly higher in people with existing high blood pressure ().

May Reduce the Risk of Heart Disease

Several studies have linked low magnesium levels to a higher risk of heart disease.

For instance, one study found that those with the lowest magnesium levels had the highest risk of death, especially due to heart disease ().

Conversely, increasing your intake may lower this risk. That’s because magnesium has strong anti-inflammatory properties, may prevent blood clotting and can help your blood vessels relax to lower your blood pressure ().

An analysis of 40 studies with more than one million participants found that consuming 100 mg more of magnesium each day reduced the risk of stroke and heart failure by 7% and 22%, respectively. These are two major risk factors for heart disease ().

May Improve Blood Sugar Control in Type 2 Diabetes

People with type 2 diabetes often have low magnesium levels, which may worsen the condition, as magnesium helps regulate insulin and moves sugar out of the blood and into the cells for storage ().

For instance, your cells have receptors for insulin, which need magnesium to function properly. If magnesium levels are low, your cells can’t use insulin effectively, leaving blood sugar levels high (, , ).

Increasing magnesium intake may reduce blood sugar in people with type 2 diabetes.

An analysis of eight studies showed that taking a magnesium supplement significantly reduced fasting blood sugar levels in participants with type 2 diabetes ().

However, the beneficial effects of magnesium on blood sugar control have only been found in short-term studies. Long-term studies are needed before a clear recommendation can be made.

Can Improve Sleep Quality

Poor sleep is a major health problem around the world.

Taking magnesium may improve sleep quality by helping your mind and body relax. This relaxation helps you fall asleep faster and may improve your sleep quality ().

In a study in 46 older adults, those taking a magnesium supplement daily fell asleep faster. They also noticed improved sleep quality and decreased insomnia symptoms ().

What’s more, animal studies have found that magnesium can regulate melatonin production, which is a hormone that guides your body’s sleep-wake cycle (, ).

Magnesium has also been shown to bind to gamma-aminobutyric (GABA) receptors. The hormone GABA helps calm down nerve activity, which may otherwise affect sleep (, ).

May Help Combat Migraines

Several studies have shown that low magnesium levels may cause migraines.

One study found that participants with migraines had significantly lower magnesium levels than healthy adults ().

Increasing your magnesium intake could be a simple way to combat migraines (, ).

In one 12-week study, people with migraines who took a 600-mg magnesium supplement experienced 42% fewer migraines than before taking the mineral ().

That said, most of these studies only notice a short-term benefit of taking magnesium for migraines. More long-term studies are needed before making health recommendations.

May Help Reduce Symptoms of Depression

Low levels of magnesium have also been linked to symptoms of depression.

In fact, one study in over 8,800 people found that among adults aged 65 and under, those with the lowest intake of magnesium had a 22% greater risk of this condition ().

One reason for this is that magnesium helps regulate your brain function and mood.

Several studies have shown that supplementing with magnesium may reduce symptoms of depression. Some studies even found it to be as effective as antidepressant drugs (, ).

Although the link between magnesium and depression is promising, many experts still believe that more research in this area is needed before giving recommendations ().

Summary Higher magnesium intakes have been linked to health benefits such as a lower risk of heart disease, fewer migraines, reduced symptoms of depression and improved blood pressure, blood sugar levels and sleep.

Few people meet the recommended daily intake (RDI) of 400–420 mg for men and 310–320 mg for women ().

However, this mineral is found in plenty of delicious foods ():

AmountRDI (based on 400 mg/day)
Pumpkin seeds0.25 cup (16 grams)46%
Spinach, boiled1 cup (180 grams)39%
Swiss chard, boiled1 cup (175 grams)38%
Black beans, cooked1 cup (172 grams)30%
Flaxseeds1 ounce (28 grams)27%
Beet greens, boiled1 cup (144 grams)24%
Almonds1 ounce (28 grams)20%
Cashews1 ounce (28 grams)20%
Dark chocolate1 ounce (28 grams)16%
Avocado1 medium (200 grams)15%
Tofu3.5 ounces (100 grams)13%
Salmon3.5 ounces (100 grams)9%

If you cannot meet your daily magnesium needs through foods alone, consider taking a supplement. They are widely available and well-tolerated.

Supplements that are well-absorbed include magnesium glycinate, gluconate and citrate. Avoid taking magnesium with zinc as it may reduce absorption.

It’s best to speak to your doctor before taking magnesium, since it can interact with common medications for high blood pressure, antibiotics or diuretics.

Summary Magnesium is found in many delicious foods, which makes it easy to increase your daily intake. Supplements are also well-tolerated. However, if you take medications, speak to your doctor to avoid adverse interactions.

Magnesium is a mineral involved in hundreds of cellular reactions.

It’s important for making DNA and relaying signals between your brain and body.

It competes with calcium, ensuring your heart and muscles contract and relax properly, and can even improve migraines, depression, blood pressure, blood sugar levels and sleep quality.

Yet, few people meet the recommended daily intake of 400–420 mg for men and 310–320 mg for women.

To increase your intake, eat foods rich in magnesium such as pumpkin seeds, spinach, cashew nuts, almonds and dark chocolate.

Supplements can be a handy option, but make sure to speak to your doctor if you’re taking other medications.