Magnesium

Magnesium is one of the harder nutrients to buy sensibly. It is sold as at least a dozen different compounds, and the amount of actual magnesium in each varies by a factor of six or more for the same tablet weight. The number on the front of the bottle is usually not the number that matters.

These guides work through it: what each compound is, how to read what an Australian label is telling you, what has been measured in people, and where the research runs out.

If you are starting from scratch, start with the magnesium glycinate guide. If you want to compare products you already have in front of you, elemental magnesium explained is the one that does the arithmetic.

How much magnesium are Australians actually getting?

In 2023 the Australian Bureau of Statistics reported that 31.3%, or 7.7 million people aged two and over, had an inadequate magnesium intake from food and beverages, measured against the Estimated Average Requirement. It was higher in adults than children, and higher in males than females.

That figure gets quoted a lot, usually without the parts that change what it means. Three are worth holding on to.

It counts food and drink only, so anyone already taking a supplement is included in the 31.3%. Inadequate intake measured against a population reference is not the same thing as deficiency, and the ABS notes that the effects of magnesium deficiency are rare. And magnesium was the one mineral in that release where the picture improved between 2011 to 2012 and 2023, while iodine, iron and zinc went the other way.

So it is a reason to pay attention to what you eat, not evidence that a third of the country needs a supplement.