What is magnesium deficiency?

Magnesium is an essential mineral for healthy muscles, bones, nerves and blood sugar levels.

Magnesium deficiency is when your body does not have enough magnesium to function normally.

Read more on magnesium and your health.

What are the symptoms of magnesium deficiency?

Magnesium deficiency can cause:

• low appetite
• nausea and vomiting
• fatigue and weakness

What causes magnesium deficiency?

Magnesium deficiency is more likely in people who:

• do not eat enough magnesium (especially older people, or those who don't have enough to eat)
• have type 2 diabetes
• have digestive problems — such as Crohn's disease
• have long-term vomiting or diarrhoea
• have kidney problems
• use some medicines long-term — such as diuretics or reflux medicines
• have alcohol dependency

Magnesium deficiency is rare in healthy people.

When should I see my doctor?

If you have any symptoms of magnesium deficiency and are worried, speak to a doctor. Your doctor can check your magnesium levels with a blood test.

How is magnesium deficiency diagnosed?

Magnesium deficiency is diagnosed with a blood test or a urine test.

Your doctor may refer you for a blood or urine test, if you have:

• symptoms of magnesium deficiency
• abnormal calcium levels
• abnormal potassium levels

How is magnesium deficiency treated?

Magnesium deficiency is usually treated with magnesium supplements. Sometimes these can give you diarrhoea. If this happens, your doctor can adjust your dose.

If your levels are very low, you may need to be given magnesium by an intravenous (IV) drip in hospital.

Speak to your doctor or pharmacist before taking a magnesium supplement.

What are the complications of magnesium deficiency?

Health problems can occur if you have low magnesium levels for a long period of time.

In the short-term, severe magnesium deficiency can lead to:

• muscle spasms
• abnormal heart rhythms (arrhythmias)
• cardiac arrest

Health problems linked to magnesium deficiency are rare.

Long-term magnesium deficiency can increase your chance of developing health problems, including:

• high blood pressure and heart disease
• diabetes
• osteoporosis
• migraine headaches

Magnesium deficiency can also cause hypocalcemia (low serum calcium) or hypokalemia (low potassium levels).

It’s rare to have too much magnesium from your diet. You can have too much magnesium from taking too many magnesium supplements.

Can magnesium deficiency be prevented?

To prevent magnesium deficiency, eat a healthy, balanced diet containing magnesium-rich foods. These include:

• nuts and seeds
• leafy green vegetables
• legumes
• whole grains — brown rice
• milk and milk products

Resources and support

Read more on foods high in magnesium and magnesium supplements.

Visit Nutrition Australia for more information about keeping healthy.

See Eat for Health has tips on healthy eating and preventing magnesium deficiency.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.