Magnesium | Pathology Tests Explained

Magnesium (Mg) is a mineral that is essential for healthy muscles, nerves, bones and blood sugar levels. Not getting enough magnesium in your diet can increase the chance of health problems such as:
Magnesium is needed for many processes in your body.
Magnesium is important:
You can get magnesium from food or from a supplement. Foods high in magnesium are:
How much magnesium you need depends on your age, sex and life stage.
See the table for magnesium requirements across your lifespan.
| Stage of Life | Recommended dietary intake* of magnesium (milligrams per day) |
|---|---|
| 0-6 months | 30 |
| 7-12 months | 75 |
| 1-3 years | 80 |
| 4-8 years | 130 |
| 9-13 years | 240 |
| 14-18 years males | 410 |
| 14-18 years females | 360 |
| 19-30 years males | 400 |
| 19-30 years females | 310 |
| 31-70+ years males | 420 |
| 31-70+ years females | 320 |
| During pregnancy | 350 to 400, depending on age |
| While breastfeeding | 310 to 360, depending on age |
Yes. Low magnesium levels can be caused by poor diet or some health conditions.
Taking some medicines for a long time can lead to low magnesium levels, such as:
Over time, low magnesium levels can cause problems with the flow of nutrients in and out of your cells. This includes the flow of calcium and potassium.
If you don't have enough magnesium in your body, you might have symptoms such as:
Severe magnesium deficiency can cause:
People with magnesium deficiency have a greater chance of developing:
You can't get too much magnesium from food because your kidneys will clear out extra magnesium through your urine (pee).
Normally, magnesium poisoning or toxicity happens when too much magnesium is taken in the form of:
Magnesium poisoning or toxicity is rare.
You should not take supplements with more than the recommended amount of magnesium, as this can cause:
Too much magnesium can lead to an irregular heartbeat or cardiac arrest.
Speak with your doctor if you're worried about your magnesium levels. Your doctor may test your levels with a magnesium blood test.
Read more about foods high in magnesium and when you may need to take supplements.
Nutrition Australia (Opens in new tab) has information about how to keep you and your family healthy through diet.
See Eat for Health for more information about magnesium and your health (Opens in new tab).
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.
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Last reviewed: April 2025



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