Magnesium is a phenomenal mineral which is required for over 300 reactions in the body. Some of its many functions include its role in thyroid hormone production, oestrogen metabolism, insulin sensitivity (think PCOS, weight management and diabetes), carbohydrate metabolism (think sugar cravings), energy production, sleep, muscle contraction (think period pain, endometriosis, blood pressure, heart health), neurotransmitter production such as GABA and serotonin – meaning it plays a critical role in mental wellbeing and can help to alleviate anxiety and depression. Our bodies also use extra amounts of magnesium during times of stress, which can make us more susceptible to feeling stressed! In short, magnesium is critical for optimal human health and can be used therapeutically in the management of many disease states.

How much magnesium do we need?

The Recommended Dietary Allowance (RDA) for magnesium is 320mg for women, 400-420mg for men, 350-360mg/day during pregnancy and 310-320mg/day during lactation, as set by the National Health and Medical Research Council (NHMRC).


Magnesium deficiency during pregnancy is associated with higher health risks for both the mother and baby, including intrauterine growth restriction, low birth weight, gestational diabetes, pre-eclampsia and preterm labour.

What are the consequences of low magnesium intake?

Aside from the above concerns around pregnancy, some of the many signs and symptoms that can be caused by low magnesium levels include*:

  • Anxiety
  • Depression
  • Hyperactivity
  • Poor stress tolerance – easily overwhelmed
  • Blood sugar dysregulation, insulin resistance and diabetes
  • Polycystic ovarian syndrome (PCOS)
  • Conditions of excess oestrogen – due to its involvement in oestrogen metabolism
  • Blood pressure and heart disease
  • Irregular heart beat
  • Sleep disorders and insomnia
  • Headaches and migraines
  • Osteopenia and osteoporosis
  • Muscle spasms or cramps
  • Pins and needles
  • Pain – including nerve pain
  • Vitamin D deficiency

*Please note: the above signs and symptoms can also be indicative of other nutrient deficiencies and/or health conditions. A nutrient deficiency should not be assumed and supplementation should not be commenced without seeking professional advice from your healthcare practitioner.

Which foods contain magnesium?

  • Dark green leafy vegetables such as spinach and kale
  • Almonds
  • Cashew nuts
  • Brazil nuts
  • Pumpkin seeds
  • Flax seeds
  • Chia seeds
  • Avocado
  • Bananas
  • Cacao powder
  • Dark chocolate
  • Chickpeas
  • Lentils
  • Soybeans – organic
  • Tofu – organic
  • Tempeh – organic
  • Buckwheat
  • Quinoa
  • Brown rice

Does anything reduce the absorption of magnesium?

  • Like iron and zinc, there are many substances which can decrease the absorption of magnesium, including:
  • Calcium can inhibit magnesium absorption as they use the same transporters to cross the small intestine into the blood, so they can compete for absorption. Take magnesium supplements 2 hours away from dairy and any calcium supplements.
  • Phytic acid found in whole grains (brown rice, quinoa, buckwheat, oats etc) and legumes (chickpeas, lentils, beans etc) bind to magnesium in the gastrointestinal tract and prevent its absorption. Correct preparation of legumes and grains should be emphasised in order to optimise absorption of magnesium and other minerals. Rinsing and soaking these foods prior to cooking helps to de-activate phytic acid.
  • Digestive/malabsorption issues such as IBS, undiagnosed/unmanaged coeliac disease and inflammatory bowel conditions i.e. Crohn’s disease and Ulcerative Colitis
  • Long-term vomiting or diarrhoea
  • Kidney problems
  • Long-term use of diuretics
  • Some pharmaceutical medicines (e.g. fluid altering medications and stomach acid/reflux medications) if taken for long periods of time*
  • Alcoholism

*Speak to your healthcare practitioner before commencing any supplement use. Do not cease taking prescription medication unless advised by your healthcare practitioner.

To summarise:

Magnesium is crucial for health and wellbeing and deficiency can both cause and contribute to all sorts of health conditions. Magnesium deficiency is common due to our processed diets and high stress levels, so supplementation can be beneficial. There are different types of magnesium, some are more protective to the heart, some act as laxatives, some are well absorbed, some are not – speak to a qualified health practitioner to ascertain which type of magnesium is right for you. Concentrating on getting enough whole foods into your diet should be of top priority always but especially in times of stress where magnesium levels are used at a higher rate.

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