Nutrition Guide: What range should your magnesium be?

November 11, 2025 •

4 min read

Less than 1% of the body's total magnesium is in the blood serum, making a single blood test sometimes an incomplete picture of overall status. To gain a full understanding of your mineral health, it's essential to know what range should your magnesium be for optimal function, not just whether you have a deficiency.

Quick Summary

This article outlines the normal serum magnesium range, details the causes and symptoms of both low (hypomagnesemia) and high (hypermagnesemia) levels, and explores how to achieve balance through diet.

Key Points

Normal Serum Range: For adults, normal serum magnesium levels typically fall between 1.7 and 2.2 mg/dL, though lab values may vary.
Limited Blood Test: A standard serum blood test only measures a small portion of the body's total magnesium, so it may not reflect a total body deficiency.
Hypomagnesemia Causes: Low magnesium can result from inadequate dietary intake, gastrointestinal disorders, certain medications, chronic alcoholism, or diabetes.
Hypermagnesemia Risk: High magnesium levels are rare but can occur with kidney failure or excessive supplementation, causing serious symptoms.
Dietary Sources: Excellent food sources of magnesium include leafy greens, nuts, seeds, legumes, and whole grains.
Choosing Supplements: Different forms of magnesium supplements vary in absorption rates; well-absorbed forms like citrate or glycinate are often recommended.
Professional Consultation: It is essential to consult a healthcare provider for accurate diagnosis, testing, and treatment recommendations for any magnesium imbalance.

The Normal Serum Magnesium Range

For most healthy adults, the normal range for serum magnesium is approximately 1.7 to 2.2 milligrams per deciliter (mg/dL), or 0.70 to 1.15 millimoles per liter (mmol/L). However, it is important to remember that these ranges can have slight variations depending on the laboratory and individual health factors. Healthcare professionals assess these results in conjunction with a person's medical history and symptoms.

Why a Blood Test Isn't the Whole Picture

While a serum magnesium test is the most common method, it has limitations because it measures only the magnesium in your blood—a small fraction of the body's total amount. The majority of magnesium (50% to 60%) is stored in bones, and most of the rest is within cells in soft tissues. This means that a person could have normal serum levels while having a total body magnesium deficit. For this reason, assessing true magnesium status can be challenging, and a comprehensive evaluation may require looking at a variety of factors, including diet, symptoms, and other specialized tests.

Hypomagnesemia: When Levels Are Too Low

Low magnesium, known as hypomagnesemia, is surprisingly common, with studies indicating a significant portion of the population may not consume the recommended daily amount through diet alone. The body works hard to prevent a deficiency, with the kidneys conserving the mineral when intake is low. However, chronic low intake or other health issues can lead to depletion. Initial symptoms can be subtle and include:

Fatigue and weakness
Loss of appetite
Nausea and vomiting
Personality changes

If the deficiency worsens, more severe symptoms can develop, including:

Muscle cramps and spasms
Tingling or numbness
Abnormal heart rhythms (arrhythmias)
Coronary spasms
Seizures

Common causes of hypomagnesemia include:

Dietary factors: Not eating enough magnesium-rich foods.
Gastrointestinal issues: Conditions like Crohn's disease, celiac disease, or chronic diarrhea can impair absorption.
Chronic alcoholism: Poor dietary intake and increased urinary excretion contribute to depletion.
Certain medications: Long-term use of diuretics, proton pump inhibitors (PPIs), and some antibiotics can increase magnesium loss.
Kidney disease: The kidneys' ability to retain magnesium can be impaired.
Diabetes: High blood glucose can lead to increased urinary magnesium loss.

Hypermagnesemia: When Levels Are Too High

An excessively high level of magnesium (hypermagnesemia) is much rarer than a deficiency and is typically caused by impaired kidney function or over-supplementation, not from food alone. In a healthy individual, the kidneys effectively filter and excrete excess magnesium. Symptoms of hypermagnesemia usually appear when levels significantly exceed the normal range and can include:

Nausea and vomiting
Low blood pressure (hypotension)
Facial flushing
Lethargy and drowsiness
Muscle weakness
Impaired breathing
Severely high levels can lead to irregular heartbeat, coma, and even cardiac arrest.

Increasing Magnesium Naturally

The best way to manage your magnesium levels is through a healthy diet. Many common foods are excellent sources of this essential mineral. Foods rich in magnesium:

Leafy Greens: Spinach, Swiss chard.
Nuts and Seeds: Pumpkin seeds, chia seeds, almonds, cashews.
Legumes: Black beans, edamame, lentils.
Whole Grains: Brown rice, whole wheat bread, shredded wheat cereal.
Other Sources: Dark chocolate, avocados, tofu, bananas, and salmon.

Magnesium Supplementation and Absorption

If dietary changes are not enough, a healthcare provider may recommend a supplement. It's crucial to choose the right form, as some are absorbed more effectively than others. Excessive supplementation can lead to gastrointestinal side effects like diarrhea. For adults, the upper intake level (UL) for magnesium from supplements is 350 mg per day.


Magnesium Form	Primary Use/Benefit	Absorption Rate	Common Side Effects
Magnesium Glycinate	May improve sleep and anxiety.	Higher absorption; well-tolerated.	Generally mild; less likely to cause diarrhea.
Magnesium Citrate	Often used as a laxative.	Higher absorption rate.	Can cause gastrointestinal distress and diarrhea.
Magnesium Oxide	Common and inexpensive; used for heartburn/constipation.	Lower absorption rate.	Can cause laxative effects.
Magnesium Lactate	Often used to treat deficiency.	Higher absorption rate; well-tolerated.	Minimal side effects; good for sensitive individuals.
Magnesium Chloride	Often used topically or in mineral water.	Well-absorbed.	Can cause diarrhea in some individuals.

Understanding Your Magnesium Test Results

If your doctor has ordered a magnesium test, it is likely because you have symptoms of a possible imbalance or a pre-existing condition that puts you at risk, such as kidney disease, diabetes, or alcoholism. While a simple serum test is a starting point, other methods may be used to get a more accurate picture of your overall magnesium status, including:

Red Blood Cell (RBC) Magnesium Test: Measures magnesium within red blood cells, which can provide a better indicator of cellular magnesium stores.
24-Hour Urine Test: Measures how much magnesium your kidneys excrete over a day.
Magnesium Loading Test: Evaluates how the body absorbs and retains a dose of magnesium, offering insights into whole-body status.

Always discuss any test results with your healthcare provider. They will provide the most accurate interpretation based on your health history and individual circumstances. For general information on nutrition, the National Institutes of Health's Office of Dietary Supplements offers extensive resources.

Conclusion

Understanding what range your magnesium should be starts with knowing the normal serum levels, but it's equally important to recognize the limitations of a single test. The body's magnesium is tightly regulated, but factors like diet, chronic disease, and medication can disrupt this balance, leading to either deficiency or, less commonly, excess. By consuming a diet rich in magnesium-containing foods and consulting with a healthcare professional about appropriate supplementation or specialized testing when necessary, individuals can effectively manage their magnesium status and support their overall health and well-being.

Frequently Asked Questions

The normal serum magnesium range for a healthy adult is typically between 1.7 and 2.2 mg/dL (0.70 to 1.15 mmol/L), though normal ranges can vary slightly between different laboratories.

Common symptoms of low magnesium (hypomagnesemia) can include fatigue, muscle cramps, weakness, loss of appetite, nausea, and in more severe cases, an irregular heartbeat or seizures.

It is highly unlikely to consume too much magnesium from food alone in healthy individuals, as the kidneys are very efficient at excreting excess amounts. High levels are usually caused by impaired kidney function or excessive supplement intake.

Conditions that can lead to magnesium deficiency include gastrointestinal disorders (like Crohn's disease), kidney disease, poorly controlled diabetes, and chronic alcoholism.

Excellent food sources of magnesium include pumpkin seeds, almonds, spinach, black beans, whole grains, avocados, and dark chocolate.

Some forms of magnesium are better absorbed than others. Forms that dissolve well in liquid, like magnesium citrate, lactate, or glycinate, are typically more bioavailable than magnesium oxide.

A doctor may order a magnesium test if you have symptoms of a deficiency, a health condition that affects mineral balance (like kidney disease or diabetes), or if you are taking medications that can alter magnesium levels.

High magnesium levels (hypermagnesemia) can cause symptoms like nausea, muscle weakness, lethargy, low blood pressure, and impaired breathing. It is a serious condition, especially in those with kidney problems.