What Are the Symptoms of Low Magnesium, and How Do You Treat It?

Magnesium is a mineral that the body uses for many processes. You’ve probably heard more about other electrolytes — like sodium, potassium, and calcium. But like these other electrolytes, magnesium plays a critical role in your nervous system, heart health, and metabolism. 

Low magnesium levels, also called “hypomagnesemia,” can cause a variety of problems. Some are more serious than others. Here, we’ll discuss the symptoms, causes, and diagnosis of this condition, along with treatment options.

Symptoms of magnesium deficiency

Magnesium deficiency can cause a range of symptoms in different parts of the body. Many of the symptoms relate to the role of magnesium in the electrical conduction of your nervous system and heart. 

Some of the symptoms of magnesium deficiency include:

• Weakness and fatigue

• Tremors or muscle twitching

• Muscle cramping 

• Heart palpitations or heart arrhythmias

• Numbness

• Seizures 

• Confusion or mood changes 

In many cases, magnesium deficiency is linked with low levels of other important electrolytes. Low calcium and low potassium are especially common. That’s partly because low levels of these electrolytes share common causes. 

Causes of magnesium deficiency

There are several causes of low magnesium levels. 

Low magnesium intake

This can happen if you’re malnourished or don’t eat enough foods that have magnesium. The good news is that there are a lot of foods that are rich in magnesium (check out the list below).

Gastrointestinal conditions

Intestinal conditions can affect how magnesium is absorbed in the gut. This can happen even if you eat enough magnesium in your diet. Examples of these conditions include:

• Celiac disease

• Inflammatory bowel disease 

• Gastric bypass surgery 

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You can also lose magnesium through your digestive tract when you vomit or have diarrhea for any reason. 

Kidney conditions 

Health conditions can affect how your kidneys process magnesium. The result is that your kidneys pass extra magnesium through urine. And this can cause a magnesium deficiency.

These conditions include kidney diseases, as well as others that affect the kidneys, such as:

• High blood sugar from diabetes 

• High calcium levels 

• Thyroid disease

• Bartter syndrome and Gitelman syndrome, two inherited conditions

Medications

Certain medications can lead to magnesium deficiency. Diuretics, for example, can increase the amount of magnesium passed through the urine. And proton pump inhibitors (PPIs) can affect the amount of magnesium absorbed in the gut. 

Medications that can lead to low magnesium include:

• Diuretics, like hydrochlorothiazide

• Antibiotics, like aminoglycosides 

• Chemotherapy medications, like cisplatin

• PPIs, like pantoprazole

• Laxatives

Heavy alcohol intake

Regular heavy drinking can lead to magnesium deficiency in several ways, such as:

• Not eating enough while drinking alcohol or afterward

• Magnesium not being absorbed well in the intestine

• Peeing more often, meaning more magnesium is passed

Other causes

The causes of magnesium deficiency aren’t limited to the conditions above. Your magnesium levels go up and down, based on changes in your body and levels of other electrolytes. Many different health conditions can affect how much magnesium in the blood. Some examples include:

• Inflammation of the pancreas (pancreatitis) 

• Advanced pregnancy 

• Electrolyte loss from excessive sweating or burn injuries 

• Hyperaldosteronism (increased levels of the hormone aldosterone in the body, which can be caused by many different health conditions) 

How to test for magnesium deficiency

To diagnose hypomagnesemia, a healthcare professional can check the level of magnesium in your blood. A normal magnesium level is 1.7 mg/dL to 2.2 mg/dL. So a level at or below 1.6 mg/dL is considered magnesium deficiency. 

But most people don’t experience any symptoms until the magnesium level is below 1.2 mg/dL.

Treatment for magnesium deficiency

Treatment for low magnesium levels includes oral (by mouth) magnesium supplements. If your levels are severely low or cause symptoms, intravenous (IV) magnesium may be a better option.

Depending on the cause of your low magnesium level, there are also medications — aldosterone antagonists — that can help decrease the loss of magnesium in the urine. 

Your primary care provider can help you figure out the underlying cause and decide how to best manage your low magnesium level. 

But milder cases of magnesium deficiency may not always need supplements or medications for treatment. Sometimes, all that’s needed is eating more foods with magnesium.

Foods for magnesium deficiency 

If your magnesium is low because you aren’t getting enough in your diet, you can eat more foods high in magnesium:

• Nuts and nut butters — especially almonds, peanuts, and cashews 

• Spinach

• Grains, like rice and whole-wheat breads and cereals 

• Black beans and edamame 

• Soy milk

• Yogurt

• Potatoes 

A serving of each of the above foods contains 40 mg to 80 mg of magnesium. Experts recommend that adults consume 400 mg of magnesium every day. This may be easier than you think. For example, a small serving of pumpkin or chia seeds contains up to 150 mg of magnesium.

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Written by:

Joanna Jan, MD

Joanna Jan, MD, is board-certified in internal medicine and licensed to practice medicine in the state of Pennsylvania. In 2017, she received her board certification from the American Board of Internal Medicine.

Edited by:

Katie E. Golden, MD

Katie E. Golden, MD, is a board-certified emergency medicine physician and a medical editor at GoodRx.

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