7 Magnesium Benefits: What Magnesium Does for Your Body

Key takeaways

• Magnesium supports normal muscle and nerve function, bone health, blood sugar regulation, blood pressure and heart rhythm.

• Adults age 31 and older generally need 420 mg of magnesium per day for men and 320 mg for women.¹

• Leafy greens, beans, nuts, seeds and whole grains are good sources of magnesium.

• Magnesium supplements come in different forms. Magnesium citrate and magnesium chloride are generally more bioavailable than magnesium oxide.¹

• Too much magnesium from supplements can cause diarrhea, nausea and abdominal cramping and may interact with certain medications.

What is magnesium good for?

Your body uses magnesium in more than 300 enzyme systems involved in energy production, protein and DNA synthesis, and the movement of calcium and potassium across cell membranes.¹ These processes help support nerve signals, muscle contractions and normal heart rhythm. Magnesium also plays a role in blood sugar control and blood pressure regulation.¹

7 magnesium benefits and what they do for your body

Magnesium benefits the body in several ways, but it’s important to separate the mineral’s established roles from claims about what magnesium supplements can do.

1. Supports bone health

Magnesium contributes to the structure of bone and works alongside nutrients such as calcium and vitamin D as part of normal bone metabolism.¹

Getting enough magnesium is one part of supporting bone health as you age, along with adequate calcium, vitamin D, protein and regular physical activity.

2. Helps regulate blood pressure and heart rhythm

Magnesium plays a role in maintaining a healthy heart by helping regulate blood pressure and supporting a normal heart rhythm.¹

Magnesium supplementation can be associated with modest reductions in blood pressure, with larger changes seen among people with hypertension or low magnesium levels.² Results vary, so magnesium should not be viewed as a replacement for prescribed blood pressure treatment and you should always consult with your physician before adjusting a medication regimen.

Magnesium works alongside potassium in this process. As Manoj Pawar, MD, FAAFP, chief medical officer at Mutual of Omaha, explains, “Potassium and magnesium are critical because they work at a molecular level to relax blood vessel walls, which helps lower overall blood pressure.”

3. Supports normal muscle and nerve function

Magnesium helps nerves to send signals and muscles to contract normally.¹ Calcium and potassium are also involved in these processes, which is why maintaining a balance of these minerals is important for normal muscle and nerve function.

Muscle cramps can occur when magnesium deficiency becomes more severe, although cramps have many possible causes and don’t necessarily point to low magnesium.¹

4. May play a role in sleep

Magnesium supports normal nerve and muscle function, which is one reason researchers are studying its connection to sleep. Magnesium bisglycinate supplementation has been associated with a small improvement in insomnia symptoms among adults who reported poor sleep, although more research is needed.³

Magnesium shouldn’t be treated as a proven sleep aid.

5. Helps regulate blood sugar

Magnesium plays a role in blood glucose regulation and helps the body process and use energy from food.¹ Be cautious, because that doesn’t mean taking a magnesium supplement will manage diabetes or replace other parts of a treatment plan.

6. Supports energy production

Magnesium is involved in the chemical reactions your body uses to produce energy.¹ Getting enough magnesium supports those normal processes, but taking extra magnesium isn’t a general treatment for tiredness or low energy.

7. Can support regular bowel movements

Magnesium is also an ingredient in some laxatives used for occasional constipation. That effect is different from magnesium’s role as an essential nutrient, and taking more supplemental magnesium than your body can absorb can also cause diarrhea or abdominal cramping.¹

If you’re considering magnesium to address a symptom or health condition, talk with your doctor before increasing your intake or starting a supplement.

How much magnesium do you need per day?

For adults age 31 and older, the recommended daily amount of magnesium is generally:¹

• Men: 420 mg per day

• Women: 320 mg per day 

Needs can differ during pregnancy and other life stages. These amounts include magnesium from food, beverages and supplements combined.

The daily limit for magnesium from supplements and medications is different. For adults, it is 350 mg per day unless a health care provider recommends otherwise. This limit doesn’t include magnesium naturally found in food.¹

Magnesium deficiency: What are the signs?

Magnesium deficiency doesn’t always cause obvious symptoms at first. As levels become lower, signs can include:¹

• Loss of appetite

• Nausea or vomiting

• Fatigue or weakness

• Numbness or tingling

• Muscle cramps

• Abnormal heart rhythm

• Seizures in more severe deficiency

Older adults and people with certain gastrointestinal diseases, type 2 diabetes or long-term alcohol use may be more likely to get too little magnesium. Some medications can also affect magnesium levels.¹

These symptoms can have many causes, so they don’t necessarily mean you have a magnesium deficiency. If symptoms persist or you’re concerned about your magnesium levels, talk with your doctor about whether testing is appropriate.

Types of magnesium supplements and what to know

Magnesium supplements come in several forms, and they aren’t all absorbed the same way. The right choice can depend on why you’re considering a supplement, your health history and any medications you take.¹

There isn’t one type of magnesium that’s best for everyone. Talk with your doctor before starting a supplement rather than choosing a form based only on a benefit advertised on the label.

How to get enough magnesium

For most adults, magnesium-rich foods are a practical place to start. Your doctor can help you decide whether a supplement makes sense based on your diet, medications and health history.

Incorporate magnesium-rich foods

Leafy greens, beans, nuts, seeds and whole grains are good sources of magnesium. Pumpkin seeds, chia seeds, almonds and cooked spinach are among the foods with more magnesium per serving.¹ If you’re looking for more ways to work these foods into meals, our guide to foods high in magnesium and potassium offers additional ideas.

A varied diet can help you get magnesium alongside fiber, protein and other vitamins and minerals. Always consult with your doctor before making significant changes to your diet, particularly if you have diabetes, kidney disease, heart disease, digestive issues or another health condition.

What are the side effects of magnesium?

Magnesium from food generally isn’t a concern for healthy people, but too much from supplements or medications can cause diarrhea, nausea and abdominal cramping.¹ For adults, the limit of magnesium obtained from supplements and medications is 350 mg per day; this doesn’t include magnesium naturally found in food.¹

Magnesium can also interact with certain medications, and people with kidney disease may have a greater risk of problems from excess magnesium. Talk with your doctor before starting a supplement, especially if you take prescription medications or have an existing health condition.¹

Simple ways to add more magnesium-rich foods

You don’t need to overhaul your diet to add more magnesium-rich foods. A few simple swaps can help:

• Add spinach to eggs or chia seeds to oatmeal or a smoothie.

• Choose almonds, pumpkin seeds or other healthy snacks that can help keep you satisfied.

• Use whole grains such as brown rice or quinoa as part of meals.

• Add spinach or other leafy greens to soups, salads or side dishes.

• Add beans or lentils to soups, salads and grain bowls.

Magnesium supports many everyday functions, from muscle and nerve activity to bone health, blood sugar regulation and heart rhythm. A varied diet can provide magnesium naturally, while supplements may make sense for some people based on their health and individual needs. Before changing your diet or starting a magnesium supplement, talk with your doctor about what’s appropriate for you.

Frequently asked questions about magnesium

What is the best time of day to take magnesium?

There isn’t one best time to take magnesium that works for everyone. Timing can depend on the type of supplement, why you’re taking it and any medications you use. Follow the product directions and ask your doctor or pharmacist about timing if you take prescription medications.¹

How is magnesium deficiency diagnosed?

A doctor may use a blood test along with your symptoms, health history and other information to evaluate magnesium levels. Because less than 1% of the body’s magnesium is found in blood, a blood test doesn’t always provide a complete picture of the body’s magnesium stores.¹

Can low magnesium affect calcium or potassium levels?

Yes. Severe magnesium deficiency can contribute to low calcium or potassium levels because magnesium plays a role in maintaining the balance of these minerals in the body.¹ If you’re concerned about low magnesium or other electrolyte levels, talk with your doctor about whether testing is appropriate.

What organ is most affected by magnesium?

Magnesium doesn’t act on just one organ. It’s used throughout the body, including the muscles, nerves, bones and cardiovascular system. The kidneys also play an important role in regulating magnesium levels by controlling how much is removed in urine.¹

Sources:

1. National Institutes of Health Office of Dietary Supplements, Magnesium: Fact Sheet for Health Professionals, Jan. 6, 2026. https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/

2. National Library of Medicine, Magnesium Supplementation and Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials, Sept. 26, 2025.https://pubmed.ncbi.nlm.nih.gov/41000008/

3. National Library of Medicine, Magnesium Bisglycinate Supplementation in Healthy Adults Reporting Poor Sleep: A Randomized, Placebo-Controlled Trial, Aug. 30, 2025.https://pubmed.ncbi.nlm.nih.gov/40918053/