What Is Magnesium Deficiency?

Magnesium deficiency, or hypomagnesemia, is a condition in which the amount of magnesium in the body is lower than expected. Magnesium is an important electrolyte (a mineral that carries an electrical charge). It works with other electrolytes, such as sodium, potassium, and calcium.

Together, these electrolytes play a role in bone development, energy production, blood pressure regulation, and much more. Hypomagnesemia occurs when a circumstance, drug, or disease alters the body’s normal intake, absorption, or excretion of magnesium.

Health Conditions Associated with Magnesium Deficiency

Verywell / Ellen Lindner

The Function of Magnesium in the Body

Magnesium is an essential mineral, or electrolyte, that the body needs to stay healthy. Magnesium plays a vital role in:

  • Bone and tooth development 
  • Energy production 
  • Blood sugar and protein levels 
  • Muscle and nerve function
  • Blood pressure regulation 
  • Heart health

Why Magnesium Is Important

Magnesium works together with other electrolytes, such as calcium, potassium, and sodium. Electrolytes are found in cells, body fluids, tissues, and bones and are essential because they:

  • Balance water in the body
  • Balance the body's acid/base (pH) levels
  • Move nutrients in and out of cells
  • Move wastes out of cells
  • Ensure nerves, muscles, the heart, and the brain work properly

When magnesium levels drop, the kidneys will regulate how much magnesium they eliminate through urination. Urine production will slow down or stop in an attempt to reserve magnesium. This is a problem because the body does not excrete the waste that builds up, damaging the kidneys and other organs. 

Electrolyte Imbalances

Low or high levels of one electrolyte can raise or lower the others, resulting in an electrolyte imbalance. Electrolyte imbalances such as hypocalcemia (low calcium) or hypokalemia (low potassium levels) can occur with severe magnesium deficiency. 

Signs and Symptoms

One of the first signs of magnesium depletion often is fatigue. However, there are other early signs and symptoms, including:

  • Loss of appetite 
  • Nausea or vomiting 
  • Fatigue 
  • Weakness
  • Muscle spasms
  • Stiffness

As magnesium deficiency worsens, the following symptoms may be present:

  • Tingling or numbness
  • Muscle cramps or contractions 
  • Tremors
  • Seizures
  • Personality or behavioral changes
  • Abnormal heart rhythms 
  • Cardiac or heart muscle damage (myocardial ischemia)
  • Coma

Causes of Magnesium Deficiency

Severe magnesium deficiency due to low dietary intake in otherwise-healthy people is uncommon because the kidneys regulate the urinary excretion (waste) of this mineral. 

However, continuously low intake, decreased absorption, or extreme losses of magnesium can lead to symptomatic magnesium deficiency. Some causes include:

  • Starvation
  • Severe diarrhea
  • Fat malabsorption (the inability to absorb or digest fat)
  • Alcoholism 
  • Gastric bypass surgery
  • Kidney malfunction
  • Some medications, including diuretics or chemotherapy

Associated Health Conditions

Certain health conditions can put people at risk for magnesium inadequacy. These disorders create conditions that lead to reduced magnesium absorption through the intestines (gut) or increase losses from the body. These health conditions include:

  • Gastrointestinal illnesses: Magnesium is absorbed in the intestines. Diseases that affect the intestines can cause chronic diarrhea and fat malabsorption, leading to magnesium loss over time. This is especially true if someone has had resection or bypass of the small intestine, particularly the ileum.
  • Type 2 diabetes: Those with type 2 diabetes often have increased urination, which can cause magnesium depletion.
  • Chronic alcoholism: Alcoholism can lead to poor nutrition, gastrointestinal problems, kidney dysfunction, liver disease, and depletion of other minerals such as phosphate and vitamin D. All of these may contribute to decreased levels of magnesium.
  • Hungry bone syndrome: After partial or total thyroid removal surgery, the body may increase how much magnesium it uses, causing hungry bone syndrome, a state of severe hypocalcemia.
  • Pancreatitis: Sudden inflammation or swelling in the pancreas can cause malabsorption and depletion of nutrients such as magnesium.
  • Kidney disease: Diseases or illnesses that cause the kidneys to have problems regulating magnesium output can cause a deficiency.   

Magnesium Deficiency May Worsen These Diseases

Studies show magnesium deficiency may worsen the following diseases: 

  • Hypertension (high blood pressure), heart disease, and stroke
  • Type 2 diabetes (the inability of the body to properly use glucose, or sugar, as fuel)
  • Osteoporosis (brittle bones)
  • Migraines (debilitating headaches)

At-Risk Populations

Older adults

Older adults often have decreased appetites, which may lead to lower nutritional intake. As normal aging occurs, the body naturally loses some ability to absorb nutrients in the intestines and regulate the excretion of nutrients in the urine. Older adults are also more likely to have chronic diseases or take medications that can deplete magnesium levels.

Infants and children

Infants and children are especially vulnerable to electrolyte imbalances related to dehydration due their smaller size and fast metabolism. This is what causes them to replace water and electrolytes at faster rates than adults.

Testing and Diagnosis

Magnesium deficiency can be hard to diagnose and test because it’s stored in soft tissue cells or within the bones. Also, the initial signs and symptoms can indicate many other health issues. However, the most common way to test for low levels is through a combination of blood, urine, or saliva concentration levels.


Prevention starts with the dietary or nutritional intake of magnesium through foods and fluids. Food high in fiber such as spinach, nuts, seeds, and whole grains are good sources of magnesium. Some cereals and bottled drinking water have added magnesium.


The goal of treatment is to manage the underlying causes of magnesium deficiency as well as replenish it through oral or intravenous (IV, through the vein) supplements. 

Oral magnesium

Oral magnesium is used for those with mild hypomagnesemia and comes in pill, powder, and liquid form. There are also different types, including magnesium oxide, magnesium citrate, magnesium gluconate, and magnesium chloride. Liquids or powders that dissolve well in fluids often have better intestinal absorption rates than pills. 

Intravenous magnesium

When a person has a severe magnesium deficiency, they may need an intravenous magnesium infusion. This is usually performed in a hospital and needs to be monitored carefully by a healthcare professional.  


Magnesium deficiency due to low dietary intake in otherwise-healthy people is uncommon. However, it’s important to include leafy green vegetables, nuts, seeds, and whole grains in your diet to prevent low levels of nutrients like magnesium.  

Your doctor may suggest oral supplements to treat mild magnesium deficiency. Be aware of the side effects of oral magnesium, which include diarrhea, nausea, and vomiting. 

Tell your doctor about all the medications you take, including supplements and over-the-counter medications such as laxatives and antacids. Drugs and supplements can sometimes interfere with each other and disrupt the balance in the body.

A Word From Verywell

Magnesium deficiency is treatable, but early detection makes treatment easier. If you are worried that you are experiencing magnesium deficiency, talk to your doctor about testing for low magnesium levels. Implementing healthy lifestyle changes, such as improving your diet and cutting down on alcohol consumption, are great ways to start making changes on your own.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Medline Plus. Fluid and Electrolyte Balance.

  2. Gragossian A, Bashir K, Friede R. Hypomagnesemia. Treasure Island, Fl

  3. Cleveland Clinic. What to Do About Magnesium Deficiency.

  4. Yu A, Chir B. Hypomagnesemia: Causes of hypomagnesemia. 

  5. National Institutes of Health (NIH) Office of Dietary Supplements. Magnesium.

  6. Rasmussen H. Nutrition in chronic pancreatitis. World J Gastroenterol. 2013;19(42):7267. doi:10.3748/wjg.v19.i42.7267

  7. Ahmed F, Mohammed A. Magnesium: The Forgotten Electrolyte—A Review on Hypomagnesemia. Medical Sciences. 2019;7(4):56. doi:10.3390/medsci7040056

  8. Hassenfield Children’s Hospital at NYU Langone. Diagnosing Fluid & Electrolyte Disorders in Children.