Magnesium is having a moment. It's blamed for poor sleep, muscle cramps, low energy and frazzled nerves, and there's a supplement on every shelf promising to fix all four. But before you add another pill to your morning routine, it's worth asking a simple question: do you actually need one? For most people, the honest answer is probably not — and here's why.
What magnesium actually does
Magnesium is a quiet workhorse. It's involved in hundreds of processes in the body — helping muscles and nerves work, keeping bones strong, and helping turn the food you eat into energy. So it genuinely matters. The question is never whether magnesium is important; it's whether you're already getting enough.
How much you need
The recommended daily amount is roughly 400–420 mg for men and 310–320 mg for women. That's a target most people can reach through food — which brings us to the good news.
Food gets you most of the way there
Magnesium is abundant in everyday, wholesome foods, especially:
- Nuts and seeds — pumpkin seeds, almonds and cashews are standouts.
- Legumes — beans, lentils and chickpeas.
- Whole grains — oats, brown rice, wholemeal bread.
- Leafy greens — spinach and other dark greens.
- A little dark chocolate — a genuinely good source, if you needed another reason.
Build meals around these regularly and you're likely covering your needs without thinking about it. Health bodies are consistent on this point: it's best to get most of your nutrients from food, with supplements reserved for when your diet genuinely falls short.
When a supplement might be worth considering
Some people are more likely to run low — for example, those who eat very little, older adults, and people with certain gut, kidney or other conditions or on medications that affect magnesium. Persistent symptoms sometimes linked to low magnesium, like muscle cramps or fatigue, have many possible causes, so they're a reason to check in with a professional rather than to self-prescribe. If a supplement is warranted, the right dose and form are best decided with your doctor or dietitian.
More isn't better
It's easy to assume a bigger dose means bigger benefits, but magnesium doesn't work that way. Getting extra magnesium from food is not a concern for healthy people, but from supplements there's an upper limit — 350 mg a day for adults — above which side effects like diarrhoea, nausea and stomach cramping become common. Very high doses can cause more serious problems, particularly for people with reduced kidney function. So the megadose bottles aren't the safe bet they might seem.
The takeaway? Magnesium is genuinely important, but it isn't a magic pill — and for most people, a varied diet with nuts, seeds, legumes, whole grains and greens does the job beautifully. If you suspect you're falling short or you have symptoms that worry you, that's a conversation to have with a professional, not a bottle to grab off the shelf.
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This article is for general information and isn't a substitute for individualised advice from your own doctor or dietitian.
Merve Tığlı, Dietitian
Sources: NIH Office of Dietary Supplements — Magnesium fact sheet; NHS — Vitamins and minerals (Others, incl. magnesium); Harvard T.H. Chan School of Public Health — The Nutrition Source: Magnesium.