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The Magic of Magnesium

Magnesium is an abundant mineral in the human body that is required for more than 300 enzymatic reactions (1). Systems that regulate protein synthesis, muscle and nerve function, blood glucose control and blood pressure all rely on magnesium. This in-demand mineral is essential for:

  • oxidative phosphorylation (the synthesis of ATP for energy production)

  • glycolysis (the breakdown of glucose for energy)

  • the development of new bone and bone structure

  • the synthesis of DNA, RNA and the master antioxidant, glutathione (which protects cells from damage)

  • nerve impulse conduction, muscle contraction and normal heart rhythm (1)

Symptoms & Consequences of Deficiency

Hypomagnesemia is defined as serum magnesium level less than 0.75 mmol/L (as indicated on a blood test result). However, serum magnesium is not necessarily an accurate reflection of one’s total body magnesium stores because magnesium is mostly contained within cells or bone (i.e., it’s not floating around in the blood). A deficiency in magnesium is likely due to a low dietary intake of magnesium-rich foods over a long period of time. Additionally, large losses of magnesium can occur as a result of some health conditions, including chronic stress, chronic alcoholism and the use of some drugs (including antibiotics, anticonvulsants, chelators, diuretics, nicotine and insulin) (1-3).

Signs and symptoms of magnesium deficiency can include (1, 4);

  • loss of appetite

  • muscle cramps

  • nausea and vomiting

  • fatigue

  • weakness

  • numbness and tingling

  • personality changes

  • insulin resistance

  • seizures

Individuals at greater risk of becoming deficient in magnesium include those affected by inflammatory gastrointestinal conditions. These include, but are not limited to; Inflammatory Bowel Disease (e.g., Crohn’s Disease), Coeliac Disease and regional enteritis. Chronic diarrhoea and/or conditions of fat malabsorption can also have a significant impact on magnesium levels and may require supplementation. In addition, resection or bypass of the small intestine (commonly due to small bowel blockage or disease), often leads to malabsorption and magnesium loss (1). Studies assessing magnesium levels in individuals who have had weight-loss surgery (gastric bypass) are limited. However, we can logically assume that the reduced absorption capacity of the gut in addition to the reduced total food intake would increase one’s risk of becoming deficient in magnesium, alongside other essential vitamins and minerals.

Individuals with insulin resistance and type 2 diabetes are also at an increased risk of magnesium deficiency. Unmanaged insulin resistance leads to higher levels of glucose in the blood (a.k.a. “blood sugar”), which means more glucose ends up needing to be filtered by the kidneys. To help the body get rid of this extra glucose, urine output is increased. Because magnesium is also regulated by the kidneys and excreted in the urine, this increased output of urine may also cause a greater excretion of magnesium, even if your body is in need of it (1). In addition, low magnesium levels have also been associated with a reduction in the action and efficiency of the hormone that helps to regulate our blood glucose levels, insulin (5, 6). But not only does magnesium play a signalling role for the action of insulin, insulin plays a regulatory role in magnesium accumulation (6). Therefore, inadequate magnesium intake may contribute to the development and severity of insulin resistance and type 2 diabetes, just as much as the development of insulin resistance and type 2 diabetes may may contribute to a deficiency in magnesium – a self-perpetuating cycle if left unmanaged.

Finally, the inevitable act of ageing increases our risk for a magnesium deficiency. As we age, the ability of our gut to get the most out of food worsens – we simply don’t absorb as much nutrition from food as we used to. In addition, ageing is associated with chronically reduced appetite, meaning that our food intake tends to decline with age. To top it off, the chronic diseases of ageing and use of multiple medications (polypharmacy) also contributes to a higher risk of magnesium deficiency (1).

If you are affected by any of the conditions mentioned, it is recommended that you consult with a qualified health professional who can assess you on an individual basis and discuss effective avenues for increasing your magnesium intake.

Therapeutic Uses of Magnesium

Type II Diabetes A number of studies have found an association between high magnesium intakes and significantly lower rates of diabetes (5, 6). This is likely due to the role of magnesium in glucose metabolism (5-8). As mentioned, low magnesium levels may worsen insulin resistance, as are they a consequence of insulin resistance (1, 6, 7). Because insulin resistance precedes type 2 diabetes, one may view magnesium as part of their management strategy for preventing diabetes.

In a 2011 meta-analysis, researchers analysed a total of 394 877 individuals across 17 studies (7). Eighty-eight percent of the analysed studies showed adequate magnesium intake to have a beneficial effect on glucose metabolism and reduction in risk of developing type 2 diabetes (7). Another meta-analysis conducted in 2007 looked at the association between magnesium intake and incidence of type 2 diabetes (8). Four of the seven studies noted a statistically significant inverse association between magnesium intake and risk of type 2 diabetes, indicating that increased magnesium intake lowers the risk of type 2 diabetes (and vice versa!) (8). Furthermore, a randomised controlled trial found that extended use of magnesium in doses higher than the general recommended dose (RDI) improves metabolic control (7). This research supports the idea that individuals with insulin resistance and type 2 diabetes require an increased intake of magnesium to maintain adequate magnesium stores. An increased magnesium intake may not only prevent a deficiency of this mineral, but also contribute to improved insulin sensitivity and glucose control in the context of a healthy diet and lifestyle (7).

Osteoporosis Magnesium intake also has also been shown to have positive effects on bone formation (1). Studies have shown positive associations between magnesium intake and bone mineral density in men and women (9). Research also found lower levels of serum magnesium in women with osteopenia, compared with women with healthy bone status (10). Additional evidence shows that increasing magnesium to the recommended daily intake (RDI) from food and/or supplements increases bone mineral density in postmenopausal and elderly women (11).

Migraine headaches There is some evidence that low magnesium levels may be related to headaches and migraines (12). One study suggested that magnesium deficiency is more prevalent in migraine sufferers than the general population (13). The researchers put forward the notion that magnesium supplementation may help in the treatment of migraines, where the patient is magnesium deficient (13). Magnesium is necessary for properly functioning serotonin receptors and may influence the synthesis and release of some neurotransmitters(12, 13). While the research is still limited, most researchers conclude that magnesium supplementation is relatively safe with possible benefit for those suffering from migraines (13, 14).

Recommended Daily Intake (RDI)

Note: these values are higher for women in the cases of pregnancy and lactation. In 2011-2012, one third of Australians over the age of two years did not meet their magnesium requirements. This was most prevalent in those aged 9 years and over (16). In teenage males between 14 to 18 years, 61% were consuming less than their requirements. In their female counterparts, this number rose to 72%.

Dietary Sources of Magnesium

Magnesium is found in plant and animal foods in varying degrees. Green leafy vegetables, nuts, seeds and whole grains are all good sources of magnesium. In general, whole foods containing dietary fibre are also good sources of magnesium. Processed food products, such as bread and breakfast cereals, are also commonly fortified with magnesium. The table below highlights the amount of Magnesium found in common foods.

Side Effects of Excessive Intake

In a healthy person, excess magnesium is excreted in the urine and does not pose any serious health risk. Excessive intake of magnesium through supplements has been known to cause or contribute to abdominal cramping, nausea and diarrhea in some individuals (1). In addition, very large doses of magnesium that are not normally recommended (5000 mg and over) have been associated with magnesium toxicity (18). The risk of toxicity increases with impaired renal function as the body cannot excrete magnesium sufficiently (19). Once again, consult with a qualified health professional if you are considering magnesium supplementation.

By Cheyenne Holman and Jessica Turton Qualified Dietitians and Nutritionists

This article provides general information from the current scientific evidence base and clinical judgement of the author. It is designed for educational purposes only and should not be substituted for medical advice. The author recommends you seek personally tailored support from a qualified healthcare practitioner before undertaking any major lifestyle change.


1. Services USDoHH. Magnesium 2018 [updated March 2 2018. Available from: - en56. 2. Sircus M. Pharmaceuticals Drive MAgnesium Levels Lower 2012 [Available from: 3. Tarasov EA BD, Zimovina UV, Sandakova EA. [Magnesium deficiency and stress: Issues of their relationship, diagnostic tests, and approaches to therapy]. Ter Arkh. 2015;87(9):114-22. 4. Milagros Huerta JR, Marit Kington, Viktor Bovbjerg, Arthur Weltman, Viola Holmes, James Patrie, Alan Rogol, Jerry Nadler. Magnesium Deficiency Is Associated With Insulin Resistance in Obese Children. Diabetes Care. 2005;28(5):1175-81. 5. Nadler JL BT, Natarajan R, Sntonipillai, Bergman R, Rude R. Magnesium deficiency produces insulin resistance and increased thromboxane synthesis. Hypertension. 1993;21(6 Pt 2):1024-9. 6. Paolisso G SA, D'Onofrio F, Lefebvre P. Magnesium and glucose homeostasis. Diabetologia. 1990;33(9):511-4. 7. Martha Rodriquez-Moran LESM, Graciela Zambrano Galvan, Fernando Guerrero- Romero. THe role of magnesium in type 2 diabetes: A brief based-clinical review. Magnesium Research. 2012;24(4):156-62. 8. S.C. Larsson AW. Magnesium intake and risk of type 2 diabetes: a meta-analysis. Journal of Internal Medicine. 2007;262(2). Jessica Turton 5

9. KL T. Osteoporosis prevention and nutrition. Curr Osteoporosis Rep. 2009;7(4):111- 7. 10. Mutlu M AM, Kiljc E, Saraymen R, Yazar S. Magnesium, zinc and copper status in osteoporotic, osteopenic and normal post-menopausal women. Journal of Internal Medicine. 2007;35:692-5. 11. Board FaN. Dietary Reference Intakes: Calcium, Phosphorous, Magnesium, Vitamin D and Fluoride. Washington, DC: Institute of Medicine; 1997. 12. Sun-Edelstein C MA. Role of magnesium in the pathogenesis and treatment of migraine. Expert Rev Neurother. 2009;9(3):369-79. 13. Mauskop A VJ. Why all migraine patients should be treated with magnesium. Journal of Neural Transmission. 2012;119(5):575-9. 14. Pardutz A VL. Should magnesium be given to every migraineur? No. Journal of Neural Transmission. 2012;119(5):581-5.

15. Council NHaMR. Magnesium: Australian Government; 2014 [

16. Statistics ABo. Magnesium: Commonwealth of Australia; 2015 [

17. NUTTAB 2015 [Available from: ault.aspx 18. Kutsal E AC, Eldes N, Demirel F, Polat R, Taspnar O, Kulah E. Severe hypermagnesemia as a result of excessive cathartic ingestion in a child without renal failure. Pediatric Emergency Care. 2007;23:570-2. 19. CG M. Magnesium metabolism in health and disease. Int Urol Nephrol. 2009;41(2):357-62.


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