The maximum recommended daily dose of magnesium for adults is 420 mg for males and 350 mg for females. However, some factors may influence your required dose, such as age and health conditions.

Magnesium is essential for many functions in your body, including energy metabolism and protein synthesis. It also contributes to proper brain function, bone health, and heart and muscle activity.

That said, approximately 1 in 2 people don’t get enough magnesium in their diets. This may lead to a variety of symptoms and even pose severe health complications.

Keep reading to learn more about how much magnesium is recommended to take each day.

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The table below shows the recommended daily allowance (RDA) or adequate intake (AI) of elemental magnesium for adults, infants, and children. This includes magnesium from the food and any supplements you may be taking.

Birth to 6 months (AI)30 milligrams (mg)30 mg
7–12 months (AI)75 mg75 mg
1–3 years (RDA)80 mg80 mg
4–8 years (RDA)130 mg130 mg
9–13 years (RDA)240 mg240 mg
14–18 years (RDA)410 mg360 mg
19–30 years (RDA)400 mg310 mg
31–50 years (RDA)420 mg320 mg
51+ years (RDA)420 mg320 mg

For people over 18 years of age who are pregnant, the requirements are increased to 350–360 mg per day.

Certain diseases and conditions are associated with magnesium deficiency, including:

Taking a magnesium supplement may help you increase your magnesium levels if you have a higher risk of deficiency or don’t consume enough in your diet. There are different types of magnesium, including:

Each type of magnesium supplement has a different absorption rate. This refers to how well the supplement is absorbed by your body.

Speak with a healthcare professional about which type of magnesium supplement is best for you.

Some types of magnesium supplements are commonly used to help relieve constipation, including:

These work by pulling water into your intestines, which adds water, bulk, and weight to your stool. This can help soften your stool and help ease its passage.

The standard dose for magnesium citrate is 240 milliliters (mL) per day, which can be mixed with water and taken orally. For magnesium oxide and magnesium hydroxide, the recommended dose depends on the product.

Always follow the dosage instructions. Exceeding the recommended intake may cause magnesium toxicity.

Adequate magnesium levels are important for a good night’s sleep.

A limited number of studies have studied the effects of magnesium supplements on sleep quality, making it difficult to recommend a specific daily dose.

However, a 2021 review found that older adults with insomnia who took between 320–729 mg of magnesium per day from magnesium oxide or magnesium citrate were able to fall asleep faster compared to a placebo.

People with type 2 diabetes may be more likely to have low magnesium levels. This is because high blood sugar levels may increase magnesium loss through urine, causing low magnesium levels in your blood.

The authors of a small 2018 study found that taking magnesium supplements may help regulate your blood sugar levels by managing insulin action.

After 3 months, they found that supplementing with 250 mg of magnesium per day in the form of magnesium gluconate, oxide, and lactate improved:

It’s important to speak with a healthcare professional before taking any supplements.

Magnesium deficiency may cause painful muscle cramps. As a result, some magnesium supplements are marketed to prevent or improve muscle cramping.

However, the research on magnesium supplements for muscle cramping is mixed.

For example, a 2002 study found that participants who received 300 mg of magnesium daily for 6 weeks reported fewer muscle cramps compared with those who received a placebo.

On the other hand, a 2012 study noted the ability of magnesium supplements to reduce the frequency of leg cramps during pregnancy. The authors reported that those who took 300 mg of magnesium daily experienced less frequent and less intense leg cramps, compared with those who took a placebo.

Still, more research is needed. A 2021 review didn’t find conclusive evidence that magnesium helps reduce muscle cramps.

Magnesium deficiency has been linked to depression.

In fact, taking a magnesium supplement may improve depressive symptoms in some people.

A 2017 study found that taking a total of 248 mg of magnesium (from 2,000 mg of magnesium chloride) per day improved depressive symptoms in those with mild to moderate depression.

Similarly, a 2016 study found that taking 305 mg of magnesium (from 500 mg of magnesium oxide) for 8 weeks led to significant improvements in symptoms of depression in people with low magnesium levels.

While magnesium supplements may help improve depression in people with magnesium deficiency, further research is needed to know if they can alleviate depression in those with normal magnesium levels.

Various studies on the effects of magnesium supplements on exercise performance have found mixed results.

For example, the authors of a 1992 study of athletes who took a daily magnesium dose of 365 mg concluded that athletes who aren’t deficient in magnesium are unlikely to benefit from supplementation.

However, a 2013 study found that volleyball players who took 350 mg of magnesium per day showed improved athletic performance, compared with a control group.

Similarly, a 2015 study found there are some benefits of taking an acute dose of magnesium, particularly before intense exercise.

Premenstrual syndrome (PMS) is a group of symptoms you may experience 1–2 weeks before your period.

Some research suggests that magnesium supplementation may help improve PMS symptoms.

A 1998 study found that taking 200 mg of magnesium from magnesium oxide daily improved water retention associated with PMS.

Another 2010 study found that supplementing with 250 mg of magnesium helped relieve PMS symptoms more effectively when combined with 40 mg of vitamin B6.

People who experience migraines may be at risk of magnesium deficiency due to several factors, including:

  • genetic inability to absorb magnesium efficiently
  • increased excretion of magnesium due to stress

According to a 2017 review, supplementing with 600 mg of magnesium dicitrate (which contains 97.2 mg of elemental magnesium) could be a safe and effective option to reduce the frequency of migraine attacks.

Another 2019 study found that taking 500 mg of magnesium oxide (300 mg of elemental magnesium) was as effective as a prescription drug at reducing the frequency and duration of migraine attacks over an 8-week period.

Magnesium toxicity

Magnesium toxicity is rare. However, taking certain magnesium supplements at high doses may cause diarrhea, nausea, and abdominal cramping.

The National Academy of Medicine recommends not exceeding 350 mg of supplemental magnesium per day.

It’s only recommended to take a daily magnesium supplement that provides more than 350 mg while under medical supervision.

Magnesium supplements may also interact with some medications, including antibiotics and diuretics.

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Is 500 mg of magnesium a day too much?

The highest value of recommended daily magnesium intake is 420 mg for adult males ages 31 years and over. Taking more magnesium than the recommended daily value may lead to magnesium toxicity. If you’re not sure about how much magnesium you should be taking, speak with a healthcare professional.

Is 50 mg of magnesium too much?

Consuming only 50 mg for people ages 6 months and older can lead to magnesium deficiency.

What are the 10 signs of low magnesium?

Some signs and symptoms of magnesium deficiency include:

Can you take 400 mg of magnesium all at once?

It’s best to consume your daily magnesium intake throughout the day. If you consume too much all at once, you may experience symptoms of magnesium toxicity.

Magnesium is involved in more than 300 biochemical reactions in your body and is crucial for maintaining good health.

The RDA for magnesium is 310–420 mg for adults, depending on age and sex.

Dosage recommendations may vary depending on your needs, such as to improve constipation, sleep, muscle cramps, or depression. Speak with a healthcare professional before taking a supplement, especially at higher doses.