Can You Overdose on Magnesium? What to Know

Magnesium is a very important mineral found within our body. It is found in various foods and contributes to many different regulatory functions within the body. Magnesium is also available as a supplement. But is it safe? Can you take too much of it? 

Let’s explore the question by first looking at magnesium a little closer; its role in the body, complications with its deficiency, and its benefits and safety as a supplement.

Magnesium and its Role in the Body

Magnesium is a major trace mineral that has a vital role to play within the body. It is needed in higher amounts compared to other trace minerals. It is essential for maintaining optimal health. 

It is a dietary mineral and is known as being one the most versatile of the trace minerals. It has a key role in over 300 enzyme reactions and aids in many system functions: Protein synthesis, metabolic functions, and muscle and nerve function, to name but a few.

It is stored mostly within the soft tissue and skeletal systems of our bodies; the least amount being found in the blood. The average adult contains around 25 g of magnesium.

Magnesium in food

As a dietary mineral, magnesium is consumed through the foods we eat. It is found in a variety of foods: Fruits, legumes, various seeds, whole grains, milk, fish, and many green leafy vegetables.

Low dietary intake of dietary magnesium can lead to magnesium deficiency, which we will cover below. 

Magnesium’s Role in the Body

Magnesium has many roles within the body, most predominantly in its relationship to enzymes. 

Here are a few of its major roles and health benefits:

Magnesium and Heart Health

Magnesium helps support healthy heart function. Its main function is in relation to blood pressure. Research on the role of magnesium and cardiovascular health suggests that magnesium aids in lowering blood pressure in healthy adults with acute higher blood pressure. 

Magnesium and Muscle Health

Again, magnesium aids and facilitates other essential minerals with enzyme reactions. This includes enzymes within the muscular system. Magnesium is sometimes used to alleviate stress-induced involuntary muscle twitching.

Magnesium for Stress 

Magnesium deficiency may have links to higher levels of stress, according to research published in the Nutrients journal of MDPI. This is due to its role in stress gland and hormone interactions. 

Magnesium for Bone Health

Magnesium also has a role to play in bone formation. It influences the activity of important bone cells: Osteoblasts and osteoclasts. Furthermore, it has a pivotal regulatory role when it comes to the water-soluble element, Vitamin D. It may also help increase overall bone mineral density, especially in postmenopausal women. 

Although further research is always being done, diets that meet the recommended levels of magnesium have shown to enhance overall bone health. 

Magnesium and Metabolic Health

Magnesium may have a role to play in regulating metabolic function. High blood sugar causes a diuretic effect in the body; frequent urination. This causes many water-soluble vitamins and minerals to be depleted, leading to magnesium deficiency. 

One controlled study found that a daily intake of supplemental magnesium improved insulin sensitivity and metabolic control in those with low magnesium levels.

Magnesium Deficiency

Magnesium deficiency can interfere with many of the functions mentioned above. Magnesium deficiency is most often a result of low dietary intake or metabolic complications as stated above. 

However, older adults and those who struggle with chronic alcoholism are also at risk for magnesium deficiency. 

Signs of deficiency may include but are not limited to:

• Loss of appetite

• Nausea and vomiting

• Fatigue and weakness

More severe symptoms can include seizures, abnormal heart rhymes, and lower calcium levels. 

For those who exercise frequently, low magnesium levels can lead to lactic acid buildup and can contribute to delayed onset muscle soreness (DOMS). 

Supplemental Magnesium

Magnesium is also common as a supplement and is used by many who do not consume enough magnesium in their diets. Numerous dietary surveys have shown that many people in the U.S. consumed far less magnesium in their diets than the recommended amount. 

As a supplement, the most common forms of magnesium are magnesium stearate, oxide, aspartate, citrate, glycinate, and chloride. Magnesium citrate and aspartate have shown to be better absorbed and boast a better bioavailability than the other forms. 

The uses for supplemental magnesium are many, but one of the most common reasons for taking magnesium supplements is for sleep health. It can be taken alone or found in combination with other supplements.

Magnesium for Sleep Health

Magnesium supplementation has also proven to be a natural way to help promote better sleep, especially among those who suffer from magnesium deficiencies or those who struggle staying asleep or falling asleep.

Magnesium also helps regulate a neurotransmitter called GABA (Gamma-Aminobutyric acid). This amino acid helps to slow down the communication between the brain and central nervous system. This is an important function for sleep health as it allows your brain to relax before falling asleep. 

Supplemental Magnesium Intake Amounts

Recommended Dietary Allowance (RDA)

This average daily level of intake is sufficient to meet nutrient requirements of most healthy individuals:

• 400 mg for males; 310 mg for females | Ages 19 to 30 years

• 420 mg for males; 320 mg for females | Ages 31 to 50 years

• 420 mg for males; 320 mg for females | Ages 51+ years

The Tolerable Upper Intake Level (UL) refers to the maximum daily intake unlikely to cause adverse health effects. The Food and Nutrition Board has only established a UL for magnesium for supplementation, not for dietary intake. The magnesium supplement UL amount for adults’ ranges between 310 - 420 mg, same as the RDA. 

Magnesium’s Interactions with other Medications

There are certain medications that have the potential to interact with magnesium supplements. These may include some antibiotics, diuretics, bisphosphonates, and proton pump inhibitors. 

Can You Take Too Much Magnesium?

We’ve finally reached our burning question: Can you take too much or overdose with magnesium? The short answer is: Yes. 

Of course, that is the answer with anything used in excess of its recommended amount. The overdosing has more to do with an onset of symptoms. Let’s look at a few. 

According to the Office of Dietary Supplements, magnesium taken in excess can pose health risks marked by certain symptoms.

High doses of supplemental magnesium (exceeding the UL of 400 mg) could result in diarrhea, nausea, vomiting, and abdominal cramps. 

Symptoms of more severe magnesium toxicity (serum levels of 1.74 – 2.61 mmol or more) may include:

• Extreme hypotension; low blood pressure
  
  
• Progressive muscle weakness

• Decrease in energy level and tiredness
  
  
• Difficulty breathing 

• Facial flushing
  
  
• Urine retention
  
  
• Irregular heartbeat
  
  

The Bottom Line on Magnesium

Getting enough magnesium from a balanced diet is usually not a concern for healthy individuals. At the end of the day magnesium overdose is rare. Getting too much magnesium from your diet is highly unlikely. 

In regard to magnesium supplementation, it is recommended to keep doses below the upper intake limits. In addition, it is always a wise move to tell your doctor or healthcare provider any time you plan to start taking a new dietary supplement.

Either way, magnesium is not optional in terms of health. It’s role and functions are too important to overlook. 

Sources:

Effects of oral magnesium supplementation on insulin sensitivity and blood pressure | Science Direct

Skeletal and hormonal effects of magnesium deficiency | NCBI

Oral magnesium supplementation improves insulin sensitivity and metabolic control | NCBI

Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride | Nap.edu

Magnesium - Health Professional Fact Sheet | NIH