The Magic of Magnesium

The Magic of Magnesium

Paediatric dieticians Stephanie Brown and Sophie Hall of Nutrition For Kids explain why magnesium can support children’s health.

Magnesium is a mineral found in a wide range of foods and is essential for our health. It is involved in hundreds of different processes in our body including producing energy, muscle and nerve function, building our bones, regulating the stress body’s response to stress and maintaining a balanced mood.

Although evidence is not strong, magnesium may help to improve sleep quality and duration, and in children with Attention Deficit Hyperactive Disorder (ADHD) and Autism Spectrum Disorder (ASD) it is thought to reduce distractibility and improve calm. Recent studies have also shown that magnesium supplementation can relieve asthma symptoms and migraine.

Another important role of magnesium is hormone balance. It may help both teen boys and girls during puberty when they experience hormonal dysregulation. This is one area where magnesium is just as essential for us mums! It’s particularly useful for women over 40, as it promotes progesterone, thyroid function, oestrogen detoxification, and calms the nervous system and muscles.

How much is needed?

As paediatric dietitians, we are guided by the Recommended Daily Intake (RDI) values for Australasia. As children grow they will need different amounts of magnesium, which have been outlined below.

Life Stage Recommended Amount

  • Birth to 6 months 30 mg
  • Infants 7–12 months 75 mg
  • Children 1–3 years 80 mg
  • Children 4–8 years 130 mg
  • Children 9–13 years 240 mg
  • Teen boys 14–18 years 410 mg
  • Teen girls 14–18 years 360 mg

Magnesium-rich food

Magnesium is present in a wide range of different everyday foods, including nuts, seeds, wholegrains, legumes, green vegetables, dairy products, fish and even dark chocolate! From the New Zealand Children’s National Nutrition Survey, we know that most children are getting enough magnesium from their diets alone. So in general, if your child is eating a healthy, balanced and varied diet, they should be getting plenty of magnesium. However, some children with restricted eating patterns including neurodivergent children (ADHD/ASD), or those with sensory issues may be at risk of deficiency as many of these very good sources of magnesium tend to be avoided.

Examples or Magnesium-rich foods and their amounts:

  • 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)
  • tinned tuna, 100g (109 mg)
  • non-fat yoghurt, 1 cup, (47 mg)
  • banana, 1 medium, (41 mg)
  • wholemeal bread, 2 slices, (46 mg)
  • Raisins, ½ cup, (33 mg)

Signs of deficiency

Common symptoms associated with low magnesium in children have been reported as:

  • Constipation – we often forget that the bowel is a muscle that needs to contract and relax!
  • Twitching muscles
  • Eye twitch
  • Growing pains
  • Restlessness
  • Sleep issues
  • Grinding teeth
  • Sensitivity to noise

Magnesium promotes GABA. GABA is an important brain chemical that also calms the nervous system. When GABA is low, our kids might experience agitation, irritability, anxiety, poor attention and aggression.

More severe magnesium deficiency can cause a number of different generalised symptoms such as weakness, fatigue, nausea, vomiting and loss of appetite. But can also cause muscle spasms, tremors, seizures and delirium.

In addition to low intake of magnesium from the diet, children can be at risk of deficiency if they have any conditions that affect the absorption of nutrients from their diet. This could include Coeliac and Crohn’s disease. We also tend to need more magnesium in times of stress because our bodies excrete more magnesium when we are stressed. Finally, some medications can also affect magnesium levels and we suggest you speak to your doctor if you have any concerns.

It is important to seek the advice of a health professional before commencing magnesium supplementation. Extremely high magnesium levels can cause confusion and irregular heartbeat. It is also worth noting that too much magnesium in supplements can cause diarrhoea and abdominal cramps.

Can magnesium support severe growing pains and cramp?

Even though we know that one of magnesium’s roles in the body is to support muscle relaxation and the stress response, the research on magnesium supplementation specifically for leg cramps is variable. Therefore, there is no therapeutic dose that we can safely recommend for any child without a proper evaluation. However, we do know that people have been using topical magnesium treatments such as Epsom salt baths to help alleviate muscle pain since as early as the 1660s. This may be a safer option for parents to trial in the first instance as we know that magnesium is still absorbed through the skin, but in a reduced amount compared to oral supplements.

If you have any concerns that your child is not getting enough magnesium (for these or any other reason) then we would suggest a full assessment with a paediatric dietitian, who can review your child’s current diet and identify magnesium-rich foods within your child’s restrictions or recommend appropriate supplementation.

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