Magnesium: Benefits, Daily Intake and the Best Sources

Magnesium is one of the most important minerals in the human body, yet it's often overlooked in everyday life. This mineral is involved in more than 300 enzymatic reactions, supports muscle function, the nervous system and energy metabolism, and contributes to normal bone health. Even so, many people don't reliably reach their daily requirement through diet alone. This guide shows you how magnesium works in your body, how much you need each day and which foods make it easiest to cover your needs.

What magnesium does in your body

Magnesium is an essential mineral, which means your body can't produce it on its own and depends entirely on what you get from food. Around 60 percent of all the magnesium in your body is stored in your bones, roughly 38 percent in your muscles and organs, and only about two percent circulates in your blood.

Here are its most important functions at a glance:

• Muscles and nerves: Magnesium helps regulate the excitability of muscle and nerve cells. It acts as a natural counterpart to calcium and supports the orderly relaxation of muscles after they contract.
• Energy metabolism: This mineral is essential for producing ATP, the universal energy currency of your cells. Without enough magnesium, energy production runs less efficiently.
• Protein synthesis and cell division: Magnesium is needed to build proteins and for DNA replication, which makes it especially important during phases of growth.
• Bones and teeth: Together with calcium and vitamin D, magnesium contributes to bone density and supports the normal structure of your teeth.
• Blood sugar and blood pressure: A sufficient magnesium supply can support normal insulin metabolism and healthy blood pressure.

Daily intake: how much magnesium do you need?

Nutrition bodies generally recommend the following daily reference values for magnesium intake:

• Women aged 25 and over: 300 mg per day
• Men aged 25 and over: 350 mg per day
• Pregnant women: 310 mg per day
• Breastfeeding women: 390 mg per day
• Teenagers (15 to 18 years): 350 mg (girls) or 400 mg (boys) per day

These values apply to healthy adults under normal physical demands. Your needs can be higher in certain situations: intense exercise, heavy sweating, ongoing stress, gastrointestinal conditions or the regular use of certain medications such as diuretics can all increase magnesium loss. Excessive alcohol consumption is also considered a risk factor for a magnesium shortfall.

The best dietary sources of magnesium

Magnesium is found in a wide range of foods, but it's especially concentrated in plant-based products. If you eat a varied diet and regularly include the following food groups, you can usually cover your needs through diet alone.

Nuts and seeds are among the richest sources of all:

• Pumpkin seeds: around 530 mg per 100 g
• Sunflower seeds: around 420 mg per 100 g
• Flaxseeds: around 350 mg per 100 g
• Almonds: around 270 mg per 100 g
• Cashews: around 270 mg per 100 g

Legumes are also well worth including:

• White beans (cooked): around 60 mg per 100 g
• Lentils (cooked): around 35 mg per 100 g
• Chickpeas (cooked): around 45 mg per 100 g

Wholegrain products have a clear edge over refined white-flour products, because magnesium is concentrated mainly in the outer layer of the grain. Wholegrain oats provide around 140 mg per 100 g, and wholemeal bread around 60 to 80 mg.

Leafy green vegetables such as spinach, chard or kale contain chlorophyll, whose molecule carries magnesium as its central atom, and they add plenty of other valuable micronutrients too.

Dark chocolate (70 percent cocoa or more) provides around 200 mg of magnesium per 100 g, though it's also high in calories and best enjoyed in moderation.

Low magnesium: signs and at-risk groups

A mild magnesium shortfall often goes unnoticed for a long time. More noticeable signs can include:

• muscle cramps, particularly in the calves
• muscle twitching or an involuntary flickering of the eyelids
• persistent tiredness and exhaustion
• difficulty concentrating and a sense of restlessness
• headaches
• a racing or irregular heartbeat (in more significant cases)

People who should pay particular attention to getting enough magnesium include:

• competitive athletes and people who train intensively
• pregnant and breastfeeding women
• older adults, since absorption in the gut declines with age
• people with type 2 diabetes or chronic gastrointestinal conditions
• those who take acid blockers (proton pump inhibitors) long term

If you suspect a shortfall, a doctor can check your blood magnesium levels and, if needed, recommend targeted supplementation.

Magnesium as a supplement: when does it make sense?

As a general rule, a balanced, wholefood diet is the best way to meet your magnesium needs. That said, supplements can be useful if you can't consistently get enough through food, if a doctor has identified a shortfall, or if your needs are temporarily higher, for example during intense training phases.

If you buy a magnesium supplement, it's worth paying attention to the form of the compound. Well-absorbed organic compounds include:

• Magnesium citrate: Well tolerated and quickly available, a good everyday choice.
• Magnesium glycinate (bisglycinate): Especially gentle on the stomach and often recommended if you have a sensitive digestive system.
• Magnesium malate: Good bioavailability, often used in sports supplements.

Magnesium oxide, on the other hand, is less well absorbed, yet it's still frequently found in cheaper products. Food safety authorities in Europe suggest a tolerable additional daily intake of 250 mg from supplements on top of what you get from food. Higher single doses can cause loose stools or diarrhoea. If you plan to take a supplement over the long term, it's a good idea to check with your doctor first.

Everyday tips: cover your needs with ease

With a few simple habits, you can noticeably improve your magnesium intake without turning your whole diet upside down:

1. Upgrade your breakfast: Swap cornflakes for wholegrain oats and sprinkle your porridge with a handful of pumpkin or sunflower seeds.
2. Snack on nuts: A small portion of almonds or cashews (about 30 g) in the afternoon provides around 80 mg of magnesium and helps keep hunger at bay.
3. Make room for legumes: Two to three portions of lentils, beans or chickpeas a week make a noticeable difference.
4. Choose mineral water wisely: Mineral waters with more than 100 mg of magnesium per litre can add to your daily intake. You'll find the amount on the label.
5. Go for wholegrain: Consistently choose the wholegrain option for bread, pasta and rice.
6. Enjoy dark chocolate: A square or two of dark chocolate with a high cocoa content is a tasty magnesium source for in between.

A well-planned menu that regularly includes these foods can usually cover the daily requirement of 300 to 350 mg with ease, without the need for a supplement.