Health Store Help! Volume 2: Magnesium

Health Store Help!
Volume 2: Magnesium

Ever wandered into your local health store, done a few dazed laps of the shelves, then staggered out again, completely overwhelmed by the possibilities?

How can one little store have so very many different bottles of pills and powders and potions?  What do they all do?  And what do I even need?

This blog series aims to demystify the health store, equip you with the knowledge to make smart choices, and highlight some of the products available that will give you the most bang for your buck.

Remember – naturopathic health care is all about what is right for you as an individual.  This is general advice, and all supplements should be checked with your naturopath or primary health care provider prior to starting use.


Pumpkin seeds

Magnesium is the fourth most abundant mineral in the body, with roughly a 50:50 distribution between bone and muscle/soft tissue [1].  There is not currently any simple and accurate laboratory test that can measure magnesium status in the body.  This is because less than 1% of magnesium is found in the blood, meaning that blood tests are only indicative of severe depletion [2].

What does magnesium do?
It sometimes seems like magnesium is the answer to every health concern around!  That is because magnesium is hugely important for maintaining many healthy bodily functions.  It is involved in over 300 metabolic reactions in the body including cellular energy production, cell growth and reproduction, and DNA synthesis [1].  It is also involved in many important biological processes such as:
•    Nerve conduction
•    Muscular contraction
•    Formation of bone and teeth
•    Immune function
•    Maintains normal heart rhythm
•    Production of hormones and neurotransmitters
•    Glucose and insulin metabolism
•    Relaxes muscles lining the lungs
•    Activation and metabolism of other vitamins and minerals such as vitamins D, B1, B6, as well as calcium, potassium and zinc
[1] [2] [3].

Here is a great infographic summarizing some of the main roles of magnesium in the body:

MagnesiumBenefitsv2Infographic sourced here

Signs you may be low in magnesium
Signs of magnesium deficiency include:
•    Muscle weakness, twitches, cramps and spasm (including a twitchy eyelid)
•    Vertigo
•    Lethargy, poor memory, apathy and melancholy
•    Disordered sleep and insomnia
•    Personality changes
•    Hyper-irritability and excitability (including over-reacting to sudden loud sounds such as a slamming door)
[1] [2] [3].

Why might I be low in magnesium?
The kidneys are the organ responsible for managing magnesium levels in the body.  Diuretics such as caffeine and alcohol, therefore, increase magnesium loss through the urine [2].  Untreated diabetics are at risk of magnesium deficiency for the same reason [1].  Gastrointestinal disorders such as coeliac disease, inflammatory bowel diseases, malabsorption conditions, infections, vomiting and diarrhea increase the risk of magnesium deficiency due to reduced absorption of the mineral [2].  The elevated cortisol levels of chronic stress deplete magnesium, as does high frequency exercise [2].  People with increased needs for the mineral are also at risk of being magnesium deficient, including pregnant and lactating women, asthmatics, migraine sufferers, the elderly, and athletes [3].

A UK study found that between 1940 and 1991 the amount of minerals present in our food had been steadily declining.  Magnesium had dropped by 24% in vegetables, 16% in fruit and 10% in meat [4].  That data is now over 20 years old, so it is possible that soil (and therefore food) concentrations of magnesium have since declined even further.  This provides an additional challenge when trying to ensure adequate dietary intake of the mineral.

How much do I need?
The recommended daily intake (RDI) of magnesium is 300-400mg/day [3].  Therapeutic doses of magnesium generally range between 200-600mg/day, depending on the condition being treated [2].

Where can I find magnesium in my diet?
There is no upper limit on the amount of magnesium that can be consumed in food [3], and maximizing dietary intake of magnesium is an important first step in the treatment of any condition in which magnesium deficiency or increased utilization of magnesium has been identified.

Food Sources of Magnesium

Food Sources of Magnesium
Pumpkin seeds, 2 tbsp (30g) 160mg
Good wholemeal bread, 2 slices 140mg
Chia seeds, 2 tbsp (30g) 120mg
Tempeh, 100g 115mg
Sunflower seeds, 2 tbsp (30g) 111mg
Spinach/Chard/Kale (cooked), 0.5 cup 80mg
Almonds with skin, 15 nuts (30g) 78mg
Tofu (firm), 100g 78mg
Cashews, 15 nuts (30g) 75mg
Rolled oats, 0.5 cup 59mg
Brazil nuts, 3 nuts (15g) 52mg
Tahini, 1 tbsp (15g) 48mg
Quinoa (cooked), 0.5 cup 45mg
Brown rice (cooked), 0.5 cup 43mg
Rice bran, 1 tbsp (6g) 41mg
Avocado, 0.5 medium 40mg
Banana, 1 medium 40mg
Lentils (cooked), 0.5 cup 35mg
Unsweetened cocoa powder, 1 tbsp (6g) 30mg

[3] [5]

Which supplement should I choose?
Not all magnesium supplements are equal, with some forms of magnesium far more easily utilized in the body than others.

Look for: magnesium chelate, magnesium citrate, or magnesium glycinate.

Avoid: magnesium oxide (the most common, and cheapest, form).

You also need to look carefully at the label, as it will list ‘total magnesium’ and ‘elemental magnesium’ – it’s the elemental dose that is important.  For example: ‘each tablet contains 750mg of magnesium (150mg elemental)’, means that each tablet has 150mg of available magnesium NOT 750mg. Speak to the staff in the store if you are unsure of how to read a product’s label.

What else do I need to consider?
Magnesium oxide, the most common form of magnesium in inexpensive supplements, is the primary ingredient in many laxatives.  It should be avoided as a magnesium supplement due to its poor absorption, but be especially aware of avoiding it if you already have a tendency to loose bowels!

Like all minerals, magnesium does not work alone in the body.  It requires adequate cofactors such as vitamin B6 and potassium in order to function optimally.  If considering magnesium supplementation, be aware that all nutrients exist in the body in a state of balance and supplementing one nutrient alone is rarely enough.

Remember – this is general advice and should not be used without consultation with your naturopath or primary health care provider (such as your doctor), particularly if you suffer from chronic illness or severe nutritional deficiencies.

If you would like to know more about how magnesium and other natural supplements can benefit your health, Rebecca is a consulting naturopath practicing from Randwick in Sydney.


[1] Guerrera, M.P., Volpe, S.L., & Mao, J.J. (2009). Therapeutic uses of magnesium. American Family Physician, 80(2), 157-162. Retrieved from

[2] Braun, L., & Cohen, M. (2010). Herbs and natural supplements: an evidence-based guide. (3rd ed). Australia: Churchill Livingstone Elsevier.

[3] Kotsirilos, V., Vitetta, L., & Sali, A. (2011). A guide to evidence-based integrative and complementary medicine. Australia: Churchill Livingstone Elsevier.

[4] Thomas, D. (2003). A study on the mineral depletion of foods available to us as a nation over the period 1940 to 1991. Nutrition and Health, 17(2), 85-115. Retrieved from PubMed 29 April, 2014.

[5] NUTTAB (2013). Foods that contain magnesium. Retrieved from

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