Magnesium is a mineral found naturally in many foods, including leafy green vegetables, nuts, seeds, whole grains and pulses. It is also available as a dietary supplement in several different forms, such as magnesium citrate, magnesium oxide, and magnesium glycinate.
About 60% of the body’s magnesium is stored in bones, with the rest found in muscles, soft tissues, and bodily fluids. It plays an important role in energy production, muscle contraction, nerve signaling, and maintaining a steady heart rate.1
Magnesium is involved in over 300 biochemical reactions in the body. Without enough magnesium, many systems can be affected.
Some of its main functions include:
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Supporting muscle and nerve functions.
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Helping control blood pressure.
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Maintaining normal heart rhythm.
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Helpful in bone strength.
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Contribution to energy production.
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Helping to control blood sugar levels.
Because magnesium is involved in many processes, low levels – known as hypomagnesemia – can cause a variety of symptoms.
Symptoms of Low Magnesium
Possible symptoms include:
People at higher risk of low magnesium include those with digestive disorders, type 2 diabetes, alcohol dependence, or taking certain medications such as diuretics.
Research shows that magnesium has many benefits, especially when levels are low.2
helps muscles function
Magnesium helps muscles contract and relax properly. Low magnesium levels are linked to muscle cramps, twitches and weakness. However, the evidence for magnesium supplements preventing nighttime leg cramps in healthy people is mixed.3
supports bone health
Works together with magnesium, calcium and vitamin D to strengthen bones. Adequate intake may help maintain healthy bones, especially as we age. However, magnesium alone does not prevent osteoporosis.
supports heart health
Magnesium plays a role in maintaining a regular heartbeat and supporting blood vessel function. Some studies suggest that higher magnesium intake may be associated with lower blood pressure, although supplements should not replace prescribed treatments.4
Energy levels may improve
Magnesium contributes to normal energy metabolism. Low levels can cause fatigue, weakness, and decreased exercise tolerance. If a deficiency exists, correcting it can improve energy levels.
Helps control blood sugar levels
Magnesium is involved in insulin function. Some research suggests that adequate magnesium intake may support healthy blood sugar levels, especially in people with type 2 diabetes. Magnesium should not be considered a substitute for diabetes medication.5
May help prevent migraine
Magnesium has been studied as a preventive treatment for migraine. Some evidence suggests that it may reduce the frequency in some people, although results vary.6
Can help relieve anxiety
Because of its role in nerve function and relaxing muscles, it has been suggested that magnesium may help deal with anxiety. Low magnesium levels are linked to symptoms like irritability and low mood, so correcting the deficiency could, in theory, help emotional well-being.7
Some small studies suggest that magnesium supplements may help mild anxiety, especially in people who are deficient. But there isn’t enough evidence to recommend magnesium as a stand-alone treatment for anxiety. If anxiety is ongoing, severe or affecting your daily life, it is important to talk to a health care professional about appropriate support and treatment options.
Most people can get enough magnesium through a varied diet. Good sources include:
Magnesium supplements may be helpful if a deficiency is diagnosed or strongly suspected. They are also sometimes used for specific conditions such as migraine prevention or constipation (some forms of magnesium have laxative effects).
Different forms of magnesium are absorbed differently and may cause different side effects.
For most healthy adults, magnesium from food is safe and unlikely to cause any problems.
High doses of magnesium supplements can cause:
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Diarrhea.
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Stomach cramps.
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nausea.
Very high levels, usually due to excessive supplementation or kidney problems, can cause more serious symptoms such as low blood pressure or irregular heartbeat.
People with kidney disease should not take magnesium supplements without medical supervision, as their bodies may have difficulty clearing excess magnesium.
As with all supplements, it is recommended to talk to a health care professional before starting magnesium if you have a long-term health problem or take regular medications.
Magnesium is an essential mineral involved in muscle function, nerve signaling, heart rhythm, bone strength, and energy production. Many magnesium benefits are most noticeable when levels are low, and a balanced diet usually provides enough for healthy adults.
Magnesium supplements may be useful in some conditions, such as a diagnosed deficiency or specific medical conditions, but they are not a cure-all. Higher doses can cause side effects, and they may not be suitable for everyone.
If you are concerned about your magnesium intake or deficiency symptoms, talk to a health care professional for advice rather than prescribing high-dose supplements yourself.
Is it safe to take magnesium daily?
For most healthy adults, daily intake of magnesium from food is safe and unlikely to cause harm.
Magnesium supplements can also be taken daily if recommended by a health care professional.
However, higher doses may cause diarrhea, stomach cramps, and nausea. Too much can be dangerous, especially for people with kidney problems.
If you are considering daily supplementation, it is wise to discuss it with a pharmacist or doctor, especially if you take regular medication.
Which type of magnesium is best?
There is no “best” type of magnesium – it depends on why it is being taken.
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Magnesium citrate is commonly used and may be easier for the body to absorb, but may have a mild laxative effect.
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Magnesium oxide contains high amounts of elemental magnesium but may be less absorbed.
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Magnesium glycinate is often marketed as being gentle on the stomach.
For constipation, some forms of magnesium may be effective because they draw water into the intestine. For other uses, your pharmacist can advise on appropriate alternatives.
Can magnesium help with sleep?
Magnesium plays a role in muscle relaxation and nerve signaling, which has led to interest in its potential effects on sleep. Some people report better sleep when taking magnesium, especially if they were previously deficient in it.
However, the evidence is mixed, and magnesium should not replace established treatments for insomnia. If sleep problems persist, it is important to rule out possible underlying causes.
