Mighty magnesium

One of the most important minerals in the body, magnesium provides a key contribution to several bodily processes. 

“Magnesium plays a role in over 300 enzyme reactions in the body involved in metabolism, neuromuscular transmission, muscle relaxation, blood pressure regulation and blood glucose control,” said Dr Trent Watson, Accredited Practising Dietitian and spokesperson for Dietitians Australia. 

He adds that magnesium has a major function in stabilising the structure of adenosine triphosphate (ATP) in ATP-dependent enzyme reactions, is required for energy production, and assists in bone structure and the synthesis of DNA and RNA. 

Given the many roles of magnesium in the body, it’s obvious that a deficiency would lead to some significant symptoms. 

“A deficiency can be associated with any condition where there’s a decreased intake or increased loss of magnesium, including electrolyte imbalance,” Dr Watson said. 

Conditions associated with magnesium deficiency, he says, include gastrointestinal disorders, diabetes and advanced age. 

“Alcohol abuse is also a major risk factor for deficiency,” he said. 

Community pharmacist Gerald Quigley adds that “lots of things” increase the demand for magnesium, including “excessive exercise, dehydration, hot weather and medications” – particularly medications “that drain fluid out of your body”.

Dr Watson says signs and symptoms of magnesium deficiency include fatigue, loss of appetite, tremors, muscle spasms, personality changes, nausea and vomiting, and in more serious cases, abnormal heart rate, seizures, convulsions and coma. 

Mr Quigley says magnesium deficiency may also lead to “cramps and twitches” such as “a twitching eyelash”, which is “usually the first sign”, adding that muscle cramps at night are also an indicator and a “surprisingly common” occurrence. 

He adds that magnesium is ”very important in sleep as well”. 

How can we ensure we get enough magnesium each day? While it might be tempting to reach for a supplement, the place to start, as many healthcare professionals suggest, is dietary intake. 

“Food sources of magnesium include seeds, nuts, cereals and grains through fortification, legumes, and dark leafy green vegetables,” Dr Watson said. 

Mr Quigley agrees that it’s important to “look at food first” when considering vitamin and mineral intake. 

“Magnesium-containing foods include almonds, cashews, eggs and leafy greens,” he said. “Eggs will often keep your magnesium levels up.” 

While intake of magnesium through diet is the first step in avoiding deficiency, in some instances supplementation may be required. 

Dr Watson says this may be “in conditions where magnesium absorption is reduced – for example, gastrointestinal disorders, diabetes, old age and alcohol abuse, or if intake through diet isn’t adequate”. 

“Diets that might be low in magnesium are those high in takeaway products [and] refined foods,” he said. “Where diet is poor, supplementation might be useful.” 

Dr Watson continued: “When suitable and recommended by a GP, magnesium supplementation can assist with [health issues including] constipation, indigestion [and, of course,] magnesium deficiency. 

“Having too much magnesium doesn’t pose a risk to health – unless at extremely high doses – as the kidneys will eliminate excess amounts via urine,” he said. 

“When supplementing a normal intake of magnesium, urinary excretion will occur to keep serum magnesium normal. This is common with water-soluble vitamins and minerals making them less dangerous to supplement. If too much is taken, it’s excreted out via urine.” 

However, while it might not pose health risks, supplementing magnesium in high doses can lead to “diarrhoea and abdominal cramps”, says Dr Watson.

He also advises supplementation only when it’s required – as in the case of a deficiency. 

“There isn’t evidence that supplementing magnesium when there’s not a deficiency supports health,” he said. In fact, he adds that, because any excess will simply be eliminated if taken when not required, those doing so are just “peeing money in the toilet”. 

Dr Watson also advised: “Always consult your GP and pharmacist before supplementing if you’re on any medications, as nutrient-drug interactions are common.” He adds that such medications include “antibiotics, osteoporosis medications and diuretics”. 

This article was originally published in the June issue of Retail Pharmacy magazine. To read the article as it appears in the magazine, click here.