How Does Magnesium Become Depleted in the Body?

January 9, 2026 •

4 min read

According to the National Institutes of Health, almost half of Americans don't get enough magnesium, a key mineral for over 300 bodily functions. Understanding how magnesium becomes depleted is vital to solving this common problem.

Quick Summary

Magnesium depletion results from poor diet, absorption issues, medication effects, and lifestyle. Addressing the cause is critical to maintaining adequate magnesium levels and overall well-being.

Key Points

Poor Diet: Diets rich in processed foods, sugar, and refined grains lead to low magnesium intake and increased excretion.
Malabsorption Disorders: Conditions such as Crohn's and celiac disease, or post-surgery effects from gastric bypass, can prevent magnesium absorption.
Certain Medications: Long-term use of diuretics, PPIs, some antibiotics, and chemotherapy drugs can cause significant magnesium loss.
Health Conditions: Chronic diseases, especially uncontrolled diabetes and kidney disorders, cause excess magnesium excretion, leading to depletion.
Alcohol and Stress: Chronic alcohol use increases magnesium excretion, while stress raises the body's need for the mineral.
Age: Older adults have an increased risk of low magnesium due to reduced absorption and potential medication use.

What is Magnesium and Why is it Important?

Magnesium is the fourth most abundant mineral in the body and supports energy, nerve function, muscle contractions, and blood pressure regulation. Most is stored in bones and soft tissues, with less than 1% in the blood. Balanced levels are vital for health, and disruptions can occur due to various factors, affecting how it's absorbed, used, and removed.

Dietary Factors and Lifestyle Habits

While modern diets often contribute to poor nutrient intake overall, magnesium depletion is not solely caused by low intake, although it is a significant factor. A diet high in processed foods, refined sugars, and fat is often low in magnesium.

Common dietary issues include:

Excessive Processed Foods: Refining foods like white flour and polished rice removes most magnesium.
High Sugar Intake: Diets high in sugar cause the kidneys to excrete more magnesium, leading to increased loss.
Alcohol Consumption: Alcohol acts as a diuretic, increasing magnesium excretion through the kidneys. Chronic alcohol abuse also leads to malnutrition and gastrointestinal problems that further inhibit absorption.
High Calcium Intake: Excessively high doses of calcium can compete with magnesium for absorption in the intestines, though this is primarily a concern with high-dose supplements rather than balanced dietary intake.
Antinutrients: Compounds like phytates in unrefined grains and oxalates in spinach can bind to magnesium, reducing its bioavailability.

Medical Conditions that Cause Magnesium Depletion

Chronic diseases can disrupt the body's ability to maintain healthy magnesium levels, either by impairing absorption or increasing urinary excretion. Some of the most common are:

Gastrointestinal Disorders: Conditions like Crohn's disease, celiac disease, and chronic diarrhea prevent efficient magnesium absorption. Gastric bypass surgery can also lead to malabsorption issues.
Kidney Disease: The kidneys regulate magnesium levels by controlling how much is excreted in the urine. Kidney disease or inherited tubular disorders can cause excessive magnesium loss.
Type 2 Diabetes: Uncontrolled diabetes and insulin resistance can lead to higher glucose concentrations in the kidneys, causing increased urinary magnesium loss.
Acute Pancreatitis: This condition can cause a shift of magnesium into necrotic fat tissue, contributing to depletion.

Medications that Deplete Magnesium

Certain medications are known to interfere with magnesium absorption or increase its excretion, and prolonged use can lead to significant deficiency. It's important to consult a healthcare provider if you are on long-term medication and suspect low magnesium.

Comparison of Medication Effects on Magnesium


Medication Class	Mechanism of Depletion	Example Drugs
Diuretics	Increase magnesium excretion via the kidneys.	Furosemide, hydrochlorothiazide
Proton Pump Inhibitors (PPIs)	Interfere with magnesium absorption in the gut.	Omeprazole, esomeprazole
Antibiotics	Some types increase renal magnesium loss.	Gentamicin, aminoglycosides
Chemotherapy Drugs	Can cause excessive renal magnesium wasting.	Cisplatin
Immunosuppressants	Associated with increased renal excretion.	Cyclosporine, tacrolimus

Symptoms and Risk Factors

Magnesium deficiency, or hypomagnesemia, can manifest in a variety of ways, ranging from subtle signs to severe complications. Early symptoms often include fatigue, loss of appetite, and nausea. As the deficiency progresses, more serious issues may arise.

Key signs of magnesium depletion:

Muscle twitches, cramps, and spasms.
Numbness and tingling.
Abnormal heart rhythms (arrhythmia).
Fatigue and weakness.
Migraines.
Anxiety and mood changes.

Risk factors for depletion include age, as absorption decreases with time, and chronic stress, which can increase the body's need for magnesium. Hospitalized patients, especially those in the ICU, also have a high prevalence of low magnesium.

Replenishing Magnesium Levels

Once the cause of depletion is identified, addressing it is critical for restoring magnesium levels and preventing recurrence. For many, increasing dietary intake of magnesium-rich foods is a primary step.

Foods high in magnesium include:

Leafy greens (e.g., spinach, kale)
Nuts and seeds (e.g., almonds, pumpkin seeds)
Legumes and whole grains
Dark chocolate

For more significant deficiencies, a doctor may recommend oral magnesium supplements, such as magnesium citrate or glycinate, which have higher bioavailability than magnesium oxide. In severe, symptomatic cases, intravenous (IV) magnesium therapy might be necessary for rapid correction. It is important to work with a healthcare provider to find the right approach and rule out other underlying health issues. For managing certain drug interactions, timing supplement intake several hours away from the medication can improve absorption.

Conclusion

Magnesium depletion is a multifaceted problem influenced by diet, medications, and underlying health conditions. It results not just from lack of intake, but also from poor absorption and excessive loss. Addressing these root causes allows individuals to maintain adequate levels through dietary changes, lifestyle adjustments, and, if needed, medical intervention. Recognizing magnesium status is crucial for overall health, particularly for those with chronic conditions or on long-term medication. Timely diagnosis and treatment prevent progression to more severe complications.

For additional information about magnesium and its role in the body, consider visiting the National Institutes of Health [https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/].

Frequently Asked Questions

Early signs of magnesium depletion often include fatigue, general weakness, nausea, loss of appetite, and irritability. These symptoms can be subtle and may worsen if not addressed.

While healthy foods should not be avoided, it is wise to be mindful of excessive refined grains, high-sugar processed foods, and large amounts of alcohol. High-fiber foods like bran and unsoaked grains contain phytates, and foods like spinach contain oxalates, both of which can slightly inhibit absorption, so separating them from supplements is beneficial.

Yes, chronic alcohol abuse is a significant cause of magnesium deficiency. Alcohol increases the excretion of magnesium through the kidneys, impairs intestinal absorption, and often accompanies poor dietary intake.

To maximize absorption, consume smaller, divided doses of supplements, take magnesium with a meal to stimulate stomach acid, and pair it with vitamin D and B6. Avoid taking magnesium simultaneously with high-dose calcium, zinc, or iron supplements.

Yes, older adults have a higher risk of magnesium depletion. This is due to a combination of lower dietary intake, decreased intestinal absorption with age, and a higher likelihood of being on medications that interfere with magnesium levels.

Yes, many common medications can lead to magnesium depletion. Diuretics, proton pump inhibitors (PPIs), certain antibiotics (like aminoglycosides), and chemotherapy drugs are known to either decrease absorption or increase urinary loss of magnesium.

Mild deficiency often presents with nonspecific symptoms like fatigue and nausea. Severe deficiency can lead to more serious neurological and cardiac problems, including muscle cramps, seizures, personality changes, and abnormal heart rhythms (arrhythmia).