What is magnesium?
Magnesium is a nutrient that is essential for healthy muscles, nerves, bones and blood sugar levels. If you don’t get enough magnesium in your diet over a long time, you may develop health problems such as heart attack, stroke, diabetes or osteoporosis.
What does magnesium do?
Magnesium is important for many processes in the body. It is needed for muscles and nerves to work properly, to keep blood sugar and blood pressure at the right level, and to make protein, bone, and DNA.
Low levels of magnesium over time can lead to low calcium and potassium levels. If you don’t have enough magnesium in your body, you might have symptoms such as headaches, loss of appetite, nausea, vomiting, fatigue and weakness. Very severe magnesium deficiency can cause numbness, tingling, muscle cramps, seizures, personality changes, and an abnormal heart rhythm.
People with magnesium deficiency are at greater risk of developing:
How do you get enough magnesium?
Magnesium is obtained from food or from a supplement. Foods high in magnesium include green leafy vegetables, legumes, nuts and seeds and wholegrains.
How much magnesium do I need?
Men under 30 need 400 milligrams (mg) of magnesium per day and men over 31 need 420mg a day. Women under 30 need 310mg each day and 320mg a day after 31. Pregnant and breastfeeding women, however, need more than that, approximately 350 to 360mg a day.
The recommended daily intake for children is:
- 1-3 years: 80mg
- 4-8 years: 130mg
- 9-13 years: 240mg
- boys 14-18 years: 410mg
- girls 14-18 years: 360mg
It’s important not to have more than the recommended amount of magnesium, as it can cause diarrhoea, nausea or abdominal cramps. Extremely high levels can lead to an irregular heartbeat or cardiac arrest.
Magnesium and medications
If you are taking a magnesium supplement, it can affect the way your body absorbs some medications, including bisphosphonates (osteoporosis medication) and some antibiotics.
Some prescription drugs used to treat acid reflux or stomach ulcers, and some diuretics can affect the levels of magnesium in the body. If you take very high levels of zinc supplements, this can interfere with your ability to absorb magnesium.
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Last reviewed: March 2021