Which foods are high in magnesium, and how much is in each?

Foods high in magnesium include seeds such as pumpkin, watermelon, sesame, chia and sunflower seeds; nuts such as cashews and almonds; dried beans such as soybeans, black beans and mung beans; whole grains such as brown rice and oats; and leafy greens such as spinach and morning glory. Per 100 g, dried pumpkin seed kernels have 592 mg of magnesium and raw brown rice 116 mg, while raw white rice has 25 mg. The Thai Reference Daily Intake (Thai RDI) for magnesium is 310 mg a day.

In short:

• Highest per 100 g: pumpkin and watermelon seeds, sesame, chia and sunflower seeds, cashews, soybeans, almonds
• Highest per usual serving (in the table below): pumpkin seeds, chia seeds, almonds, boiled spinach, cashews, peanuts, soy milk, black beans
• Thai vegetables with figures: spinach, morning glory, basil, okra, amaranth leaves and drumstick leaves
• Rice: brown rice has several times the magnesium of white rice, because magnesium is rich in the outer layers of the grain, which polishing removes
• Daily amount: Thai RDI 310 mg

This article is a table-based guide to how much magnesium is in foods. For what magnesium does in the body, see What does magnesium do, and which foods contain it?, and for the compounds used in products, see What types of magnesium are there, and how do they differ?

Which foods are high in magnesium?

The NIH Office of Dietary Supplements (ODS), part of the US National Institutes of Health, says magnesium is widely distributed in plant and animal foods and in drinks, and that green leafy vegetables such as spinach, legumes, nuts, seeds and whole grains are good sources. It adds that, in general, foods containing dietary fibre provide magnesium. The UK's NHS lists spinach, nuts and wholemeal bread. Magnesium is a component of bones and teeth, and contributes to the normal function of muscles and the nervous system and to normal energy-yielding metabolism.

Magnesium per 100 g of food

The figures below come from the US Department of Agriculture's FoodData Central database (SR Legacy), per 100 g of the food as described. Thai varieties, growing conditions and recipes may give somewhat different amounts.

Seeds, nuts and dried beans are listed dry and raw. They are eaten in smaller amounts than rice or vegetables, and dried beans take up water when cooked, so the next section looks at usual servings.

Seeds and nuts that Thai people snack on

Several of the foods at the top of the table are familiar Thai snacks. Dried pumpkin seed kernels have 592 mg of magnesium per 100 g, and dried watermelon seed kernels (the shelled seeds sold as melon seeds) 515 mg. Whole sesame seeds have 351 mg, raw cashews 292 mg and raw peanuts 168 mg. The figures for seeds are for the kernels, without the shell.

Thai vegetables and herbs

Leafy vegetables have less magnesium per 100 g than seeds, but they are eaten in larger amounts. Raw morning glory (water convolvulus) has 71 mg per 100 g, close to raw spinach at 79 mg. Fresh basil has 64 mg, okra 57 mg, amaranth leaves 55 mg and drumstick (moringa) leaves 42 mg.

How much magnesium is in a usual serving?

Per 100 g figures are useful for comparing foods, but people eat a handful of seeds and a plate of rice. The ODS table lists magnesium per typical serving, based on FoodData Central. The last column compares each serving with the Thai RDI of 310 mg.

Magnesium per serving

Source: ODS magnesium fact sheet, Table 2 (US servings). The share of 310 mg is our comparison with the Thai RDI.

Why do raw and cooked beans look so different?

Dried beans take up water when they are boiled, so the same weight of cooked beans holds fewer beans. In FoodData Central, 100 g of raw dried mung beans has 189 mg of magnesium and 100 g of boiled mung beans 48 mg. For soybeans, the figures are 280 mg raw and 86 mg boiled. When you compare foods, check whether a figure is for dry or cooked food, and for 100 g or a serving.

How much does milling rice change the magnesium?

Rice is eaten at almost every Thai meal, so the type of rice makes a large difference to the magnesium on the plate. In FoodData Central, raw long-grain brown rice has 116 mg of magnesium per 100 g, while raw unenriched long-grain white rice has 25 mg and raw white glutinous rice 23 mg.

Brown, white and glutinous rice

The cooked figures are lower than the raw ones mainly because cooked rice is mostly water. The gap between brown and white rice is there both raw and cooked.

Where in the grain is the magnesium?

A 2002 study from Hiroshima Prefectural University grew 11 rice cultivars under similar conditions, then milled the hulled grains layer by layer from the outside in and analysed each layer. In every cultivar, magnesium, phosphorus, potassium and manganese were extremely rich in the outer portion, while the inner portion was mostly starch. The ODS likewise says that refining grains in ways that remove the nutrient-rich germ and bran lowers magnesium content substantially. Two US Department of Agriculture researchers wrote in a 2019 review that rice is a source of magnesium, and that some minerals and vitamins in brown rice are not present in white rice after polishing.

Rice sold in Bangkok

A 2013 study from the Chulabhorn Research Institute analysed 667 food samples, including rice, animal foods, eggs, vegetables, fruits and drinking water, bought in markets, supermarkets and grocery stores in Bangkok between October 2005 and August 2008. Non-polished rice had higher magnesium, calcium, manganese, iron and selenium concentrations than polished rice. The study describes foods sold in one city over three years, not all rice grown in Thailand.

Does cooking change the magnesium in food?

Cooking changes the magnesium figures in two ways: cooking adds or removes water, and some minerals pass from food into the cooking water. A Japanese study measured the second effect directly.

What a Japanese study measured

A 1990 study from Kyoto University analysed many foods before and after cooking for nine minerals, including magnesium. Foods prepared in mass cooking kept on average about 60% to 70% of the minerals in the raw foods, and losses were particularly high from vegetables. The largest losses came from squeezing vegetables after boiling and from soaking thinly sliced food in water. Home-cooked meals gave similar results. The authors suggested eating boiled food with its soup and avoiding too much boiling. The study was done with Japanese foods and cooking methods.

Raw and boiled vegetables in FoodData Central

Spinach shows a higher figure after boiling because cooked leaves lose water and shrink, so 100 g holds more leaf. Morning glory, by contrast, shows a lower figure after boiling and draining. In Thai soups and curries, where the liquid is eaten too, minerals that pass into the water stay in the bowl.

How much magnesium do you need a day, and how much is too much?

The Thai RDI for magnesium is 310 mg a day, for the general population aged 3 and over. It counts magnesium from all foods and drinks. For the Thai reference amounts of other nutrients, see What are the Thai daily reference amounts for each nutrient? The NHS says people should be able to get all the magnesium they need from a varied and balanced diet.

Upper limits

The ODS explains that the upper limit can look lower than the daily amount because it counts only magnesium from supplements and medicines, while the daily amount counts magnesium from every source. It also says that too much magnesium from food does not pose a health risk in healthy people, because the kidneys eliminate excess amounts in the urine.

Who should talk to a doctor or pharmacist?

People who take regular medication

Magnesium can interact with some medicines, and some medicines can affect the body's magnesium. If you take medication regularly, ask a doctor or pharmacist before adding magnesium.

Pregnant and breastfeeding women

If you are pregnant or breastfeeding, talk to a doctor or pharmacist before taking any dietary supplement, including magnesium.

Dietary supplements are not intended to prevent, treat or cure any disease.