Magnesium is a mineral that is essential for healthy muscles, nerves, bones and blood sugar levels. Many foods contain magnesium, but the main sources in Australia are cereals and non-alcoholic drinks like coffee and water.

Why is magnesium important for health?

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.

People who have more magnesium in their diets have a lower risk of a heart attack or stroke and of developing type 2 diabetes. They are also likely to have a higher bone mineral density, meaning they are at lower risk of developing osteoporosis. 

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. 

How much magnesium do I need?

Men under 30 need 400 (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, in mg is:

• 1-3 years: 80mg
• 4-8 years: 130mg
• 9-13 years: 240mg
• boys 14-18 years: 410mg
• girls 14-18 years: 360mg

What are the best sources of magnesium?

Many foods and drinks contain magnesium. As a general rule, foods that are high in fibre provide magnesium. Some good sources of the mineral include leafy green vegetables – such as spinach – legumes, nuts, seeds and whole grains.

Tap, mineral, and bottled waters can also be sources of magnesium, but how much magnesium they contain depends on the brand.

You can get magnesium from the following foods:

• pumpkin seeds, 30g (156mg)
• chia seeds, 30 g (111mg)
• almonds, 30g (80mg of magnesium)
• spinach, boiled, ½ cup (78mg)
• cashews, 30g (74mg)
• peanuts, ¼ cup (63mg)
• soymilk, 1 cup (61mg)
• oatmeal, 1 cup cooked (6 mg)
• bread, whole wheat, 2 slices (46mg)
• avocado, cubed, 1 cup (44mg)
• rice, brown, cooked, ½ cup (42mg)
• milk, 1 cup (24mg)

Should I take magnesium supplements?

Most young children in Australia get enough magnesium, but more than 1 in 3 people don’t get enough magnesium every day.

People who are especially at risk of not getting enough magnesium are people with diseases like Crohn’s disease and coeliac disease, people with type 2 diabetes, older people and people who have alcoholism. 

If you have a magnesium deficiency or certain health problems, your doctor may recommend you take a magnesium supplement. Health problems that can be helped by taking a magnesium supplement include constipation, indigestion, high blood pressure during pregnancy, irregular heartbeat, asthma, cerebral palsy, chronic fatigue syndrome, headaches and osteoporosis.

You can’t get too much magnesium from your food, but it is important not to take more than the recommended dose of a magnesium supplement. Having too much magnesium from a supplement can cause diarrhoea, nausea, and stomach cramps.

Magnesium supplements can interfere with other medicines you may be taking, including antibiotics, diuretics and medicines for acid reflux or stomach ulcers. It’s always important to tell your doctor or pharmacist about any supplements or over the counter medicines you are taking.