Can magnesium cause diarrhea and bloating?

Magnesium is one of the most popular supplements in the US, and for good reason -many of us aren’t getting enough of it.

Magnesium is celebrated for its numerous health benefits, from alleviating anxiety to promoting better sleep to relieving muscle cramps.  However, if you’ve noticed an increase in diarrhea or bloating while supplementing with magnesium, your supplement might be the culprit.

You may be wondering: can magnesium cause diarrhea? The answer is yes!

Hi, I’m Kari, an integrative and functional dietitian who helps you overcome gut, anxiety, and energy issues so that you can focus on life, not symptoms!  Because that’s what you deserve!  

Magnesium can help (or hurt)

Magnesium, when taken in the right form and dosage, can effectively reduce or alleviate your symptoms.  

However, taking the wrong dose, choosing the wrong form, or even unnecessary supplementation can lead to the uncomfortable side effects of bloating, loose stools, and diarrhea. 

Keep reading to discover the secrets to unlocking magnesium's benefits for your health.

Magnesium has 100s of benefits

• Life-giving: Magnesium is the second most abundant element inside of human cells and is involved in over 300 enzymatic reactions within the body.  
• Blood sugar metabolism: Magnesium plays a crucial role in regulating blood sugar and insulin and reducing the risk of prediabetes and diabetes.
• Energy production: Magnesium serves as the primary fuel of mitochondria; magnesium aids in converting food to energy.  
• Muscle Relaxation: Magnesium is essential for muscle relaxation.
• Stress Reduction: Magnesium helps to reduce the intensity of our response to stress in our daily lives. 
• Anti-inflammatory: Magnesium contributes to reducing inflammation in the body.
• Detoxification: Magnesium is a key component in supporting our powerful detox pathways and neutralizing toxins.  
• Brain Health: The brain, which boasts the highest concentration of magnesium in the body, uses magnesium to produce the relaxing neurotransmitter GABA, which is essential for promoting deep sleep.

With so many important roles in our everyday wellness, it is no wonder that supplements are popular. Let’s chat about those now. 

Why Supplement with Magnesium?

On average, most people are depleted in magnesium and consume less than the Recommended Daily Allowance of 320-420 mg/day (SOURCE).  

Because of this, many people exhibit symptoms of magnesium deficiency and notice considerable benefits from supplementation.  In fact, it is the 9th most popular supplement among U.S. Adults (SOURCE).

Digestive issues:

For example, two-thirds of Americans experience digestive issues, with constipation being near the top of the list.  

Many people find that taking magnesium to support normal, regular bowel movements is very helpful. However, if you take too much or the wrong kind, this can definitely be the culprit when it comes to diarrhea or bloating.

Stress Support and Anxiety:

Another common reason people supplement with magnesium is due to the calming effect it has on our nervous system, brain, and adrenals.  

Magnesium is the first mineral used during the stress response, so for many people, this creates deficiency. For stress and anxiety, magnesium supplementation is often effective in supporting relaxation and reducing anxiety. 

Many other health benefits:

Other reasons you might benefit from magnesium supplementation include if you struggle with any of the following:

• Insulin resistance
• High blood pressure
• Abnormal heart rhythms
• Insomnia
• PMS
• Low vitamin D levels
• Headaches and migraines
• And much more.

In my practice, the most common reason my clients take magnesium is for constipation, to support calm, and to help with sleep. As I am able to help them find the right kind of supplement at the right dose, they feel SO much better…and they’re not having any issues with bloating or diarrhea!

Even though magnesium has so many benefits, it is possible to supplement with too much. Let’s talk through limits now. 

How much magnesium is too much?

When it comes to supplementation, there’s no one-size-fits-all answer.  

The appropriate magnesium dosage varies depending on your supplementation goals, existing medication and supplements, and your individual medical history.  

Additionally, the choice of magnesium supplement form significantly influences the effectiveness of your supplementation.

If you take an excessive amount or the wrong type of magnesium, you might experience some undesirable side effects. This might look like:

• Bloating
• Diarrhea
• Fatigue 
• Muscle weakness
• Low blood pressure.

In general, the recommended limit for taking magnesium from supplements is 350 mg. 

However, in my practice, I customize recommendations based on the patient’s individual history, lab results, and specific needs. 

It’s crucial to avoid creating a magnesium supplement routine that inadvertently leads to deficiencies in other nutrients, which is something I carefully track with my patients. This approach ensures that we optimize their magnesium status efficiently while lowering the risk of having side effects.

Let’s switch gears and explore the different kinds of magnesium that you can take as a supplement, as well as the pros and cons of each type.   

Types of Magnesium Supplements

Did you know that there is more than one kind of magnesium that you can take as a supplement? Getting the most benefits comes down to the best form and the right amount. 

The wrong kind of magnesium or the wrong dose of magnesium can lead directly to the digestive issues you’re hoping to avoid. 

Magnesium Oxide 

Effective for constipation but has the highest likelihood of causing diarrhea and bloating. 

Magnesium Citrate 

A form of magnesium with moderate bioavailability.  Is effective when used for constipation but can cause diarrhea and bloating (SOURCE).

Magnesium Malate 

Well absorbed within the digestive tract and effective at replenishing magnesium levels.  It is often used for muscle cramps or for fibromyalgia. It does have a laxative effect, and if taken in the wrong dose, could cause diarrhea or bloating (SOURCE).

Magnesium Threonate 

This form has high bioavailability and is best used for its neuroprotective qualities.  There is a low likelihood that this will cause digestive discomfort (SOURCE).

Magnesium Glycinate 

Well absorbed in the body.  Supports the production of GABA, a neurotransmitter in the brain that supports sleep and reduces anxiety.  It is very unlikely to cause digestive issues.

Test, don’t guess 

The best way to know that you’re getting the right amount of magnesium – not too much or too little – is by doing the right test. 

Skip the Standard Blood Test 

When considering evaluating magnesium levels in your body, the most common way to assess magnesium status is to do a standard blood test.  

However, just because it is common does not mean it is the best test. Because only 1% of magnesium exists in the blood, NOT in the cell, this is not the best way to evaluate magnesium levels (SOURCE).  

Again, because the majority of magnesium exists and is used inside your cells, in order to evaluate your magnesium status accurately, you must test how much magnesium is inside the cell.  

In order to do so, a blood draw assessing Red Blood Cell Magnesium (not just magnesium) is one test that could evaluate for this.  

Hair Tissue Mineral Analysis (HTMA) is best

However, a better tool is using Hair Tissue Mineral Analysis or HTMA. 

Hair tissue mineral analysis (HTMA) is a powerful tool that goes beyond traditional testing methods. 

Unlike blood tests that provide a snapshot of mineral levels at a specific moment, HTMA measures the body's mineral status over the past 90 days. 

What sets HTMA apart is its ability to analyze minerals inside the cell, where they perform their vital functions. This is particularly valuable for assessing magnesium status and other synergistic minerals that work in harmony with magnesium and gives you a comprehensive view of your mineral health.

Need Support?

As you can see, getting the benefits from your magnesium supplement can be a bit complicated.  

It’s really common for people to just grab any old bottle from the pharmacy, hope for the best, and then be discouraged and disappointed when they have digestive issues - not an ideal situation!

If you have been taking magnesium supplements and are experiencing digestive symptoms like diarrhea or bloating, it’s possible you’re using the wrong form or dose or that you are not addressing the underlying root cause of your digestive problems.  

The best initial step is to assess if supplementation is indeed necessary, and for this, a Hair Tissue Mineral Analysis is an invaluable tool. It helps identify your personal magnesium levels and requirements.   

If you’re interested in doing so, contact me to learn more.

Second, if you are having digestive issues or struggling with anxiety, you may need to delve deep into uncovering the underlying root cause.  Rather than aimlessly trying multiple supplements or interventions, gaining a comprehensive understanding of WHY you’re facing these digestive challenges is key.  

If you want to learn more about working with an expert who has helped hundreds of people achieve improvements in their gut health, contact me here to learn how we can work together.