Magnesium in Type 2 Diabetes

Not having enough of the mineral magnesium may play a role in causing or worsening type 2 diabetes. Science on this topic is still emerging. It may make sense to talk to your healthcare provider about whether magnesium testing or magnesium supplements would be appropriate for you.

This article explores the role of magnesium in the body and how low levels are linked to type 2 diabetes. Learn how to get tested and what to do to treat or prevent low magnesium.

What Is Magnesium?

Magnesium is a mineral, the fourth most common in the body. Most of it is found in the bones or in the body’s soft tissues. It plays many different important roles in many different organ systems, including the heart and muscles.

It is needed for hundreds of different chemical reactions in the body (which are triggered by specific proteins called enzymes). That means that if magnesium is low, these reactions may not work as efficiently. 

Some of the enzymes that use magnesium are involved in the body’s production and storage of energy. For example, magnesium is important for the way in which glucose (“blood sugar”) and the hormone insulin are processed. Magnesium seems to regulate the movement of glucose from the bloodstream to inside cells.

Many people don’t get enough magnesium in their diet. Particularly as they age, they don’t meet the recommendations for their magnesium intake, as recommended by the Office of Disease Prevention and Health Promotion of the Department of Health and Human Services.

But most of these people don’t know that they aren’t getting enough magnesium. Unless you have a severe magnesium deficiency, you are unlikely to have symptoms.

What’s the Connection Between Type 2 Diabetes and Magnesium?

Not all people who have type 2 diabetes have a magnesium deficiency, but many people who are deficient in magnesium do not have diabetes.

Still, there is an association between the two. If you have a magnesium deficiency, you are more likely to have type 2 diabetes. If you have type 2 diabetes, you are more likely to have a magnesium deficiency.

People who have a magnesium deficiency and type 2 diabetes are also at an increased risk of having rapidly worsening diabetes and diabetic complications.

In type 2 diabetes, people have elevated levels of glucose in the blood. Also, the body might not be responding to insulin as well as it normally would. Because magnesium is involved with processing glucose and insulin, it makes sense that low magnesium levels might worsen problems from type 2 diabetes.

Additionally, the kidneys often don’t work quite normally in some people with type 2 diabetes. The increased glucose levels can cause your body to get rid of more magnesium than it should. That’s likely part of the association between type 2 diabetes and low levels of magnesium. 

It’s not completely clear if low magnesium is one factor that might partly cause type 2 diabetes or whether low magnesium is often partly the result of having type 2 diabetes. In reality, these factors probably heighten the effects of each other.

Related Medical Conditions

Magnesium also seems to play a role in hypertension (high blood pressure) and dyslipidemia. These two medical conditions are common in people with type 2 diabetes. Although it isn’t the only factor, having low magnesium may worsen a blood pressure that is too high (hypertension).

Low magnesium may also contribute to dyslipidemia—having increased levels of certain types of cholesterol and fats (lipids) in your blood. That’s critical because dyslipidemia can increase your risk of conditions like heart attack and stroke.

Testing for Magnesium Deficiency

If you are someone with type 2 diabetes, it is reasonable to get tested to see if low magnesium is a problem for you. Unfortunately, finding out whether a person has a low amount of magnesium in their body is not completely straightforward.

Only a small percentage of the magnesium in your body is found inside your blood. The concentration of magnesium there is regulated very tightly. Your body works hard to keep the blood concentrations of magnesium in the normal range. It does this even if magnesium is depleted in other parts of your body.

That’s important because magnesium that falls too much outside the normal range can have serious side effects, like heart rhythm abnormalities.

Most commonly, clinicians order a serum magnesium test to get a sense of whether a person might be low in magnesium. Magnesium below 0.70 mM/L is defined as hypomagnesemia—low levels of magnesium in the blood.

Some researchers think this value is set too low, that the cutoff should be 0.85mM/L or higher, especially for people with diabetes.

This test is fine for detecting severe magnesium deficiencies, but it isn’t very good at identifying less serious deficiencies. A normal serum magnesium test doesn’t necessarily mean that you have an ideal amount of magnesium in your body.

You might have what researchers call “magnesium inadequacy” even if you don’t have a magnesium deficiency that can be seen on a blood test. 

A less common blood test, called ionized magnesium, may give better results. There is also another more complicated test, called the magnesium loading test, which may give even more accurate results. Sometimes it’s a good idea to get more than one type of test.

Magnesium in Other Diabetes Types 

Less is known about magnesium in other diabetes types. People with prediabetes may also benefit from getting tests for magnesium. If they are deficient, magnesium supplements might possibly decrease the risk of getting type 2 diabetes itself. 

Magnesium may also be a factor for some people with type 1 diabetes. Getting a magnesium test or tests is also reasonable for such individuals.

What If My Magnesium Tests Show I Am Deficient?

If blood tests show that you have low magnesium, your healthcare professional will probably recommend that you take magnesium supplements, at least temporarily. You may also need to repeat blood tests to see if the supplements are helping to increase your magnesium.

Unless you have a severe magnesium deficiency, oral magnesium is generally the way to go. This is available in several different formulations. Some of the easiest to absorb are:

• Magnesium lactate
• Magnesium citrate
• Magnesium chloride
• Magnesium gluconate

Medications Increasing the Risk of Low Magnesium

If you are taking certain medications, you may be even more likely to have a magnesium deficiency. Examples include:

• Loop diuretics like Lasix (furosemide)
• Thiazide diuretics like Microzide (hydrochlorothiazide)
• Proton pump inhibitors like Nexium (esomeprazole)

If you are taking a medication like this, getting a magnesium test might make even more sense. 

Should I Take Magnesium Supplements If I Have Type 2 Diabetes? 

If you have type 2 diabetes, a blood test for magnesium is probably the best place to start. Even if these tests don’t show that you have a magnesium deficiency, it may be worth discussing the role of magnesium with your healthcare provider. 

Researchers have been studying the relationship between magnesium and diabetes. Some small trials have indicated that it might help improve blood sugar in people with type 2 diabetes. But these results have been conflicting.

We don’t currently have enough data from good clinical trials to show that giving magnesium to most people with type 2 diabetes is a good idea. It may be that only people with clear magnesium deficiencies might benefit from this.

Because of the lack of definitive evidence, the American Diabetes Association does not currently recommend magnesium supplements to improve blood sugar control for people with type 2 diabetes.

In other words, they don’t recommend magnesium for most people with type 2 diabetes. But this doesn’t rule out magnesium for some people with diabetes who clearly need it.

Even though oral magnesium supplements are available over the counter, it’s not generally a great idea to take them without consulting with your healthcare professional, especially not for prolonged periods of time.

Taking too much magnesium might elevate amounts of magnesium in the blood (hypermagnesemia). This may lead to additional symptoms like weakness, nausea, and confusion.

Dietary Intake of Magnesium

Although magnesium supplements might not be what you need, people with diabetes should be thoughtful about eating enough foods that are high in magnesium. Some examples include:

• Whole grains (like wheat bran) 
• Nuts and seeds
• Beans
• Dark, leafy green vegetables (like spinach) 
• Fortified cereals

Many other fruits and vegetables can give you lesser but still important amounts of magnesium. For example, bananas, yogurt, avocado, and even chocolate contain magnesium.

The good news is that many of these foods are compatible with the diet already recommended for people with type 2 diabetes, although you will need to be thoughtful about it.

Some people may find it helpful to work with a nutritionist as part of their diabetes management. A nutritionist can give advice about diet for diabetes management, and they can also analyze your food choices to see if you are getting the recommended amount of magnesium in your diet.

Summary

Magnesium plays a role in the body’s regulation of blood sugar. Low magnesium levels are seen in some people with type 2 diabetes, but we don’t know whether one causes the other. Blood tests can detect a magnesium deficiency. Your healthcare professional may recommend magnesium supplements to address it, as well as how to get more magnesium in your diet.