How Much Magnesium Should You Take Per Day?

Considering everything magnesium does for your body, getting enough in your diet is crucial. But how much is enough? 

“From head to toe, magnesium is very important,” says Melina Jampolis, MD, a board-certified physician nutrition specialist and host of the Practically Healthy by Dr. Melina podcast. 

 It also plays a role in muscle and nerve function, healthy heart rhythm, blood glucose control, bone health, and much more.

Here’s what you need to know about getting enough.

BREAKING: Shed 42 lbs In 30 Days With This Simple Night-time Pill

Magnesium: Recommended Daily Allowances

The amount of magnesium you should get per day depends on your age, sex, and whether you’re pregnant or breastfeeding. Here’s a look at the recommended dietary allowances, or the average daily amount needed to meet the nutrient requirements of most healthy people:

The National Institutes of Health (NIH) notes that nearly half of U.S. adults (48 percent) don’t consume enough magnesium. One of the challenges is that when you eat food sources of magnesium — like green leafy vegetables, legumes, nuts, and whole grains — your body absorbs only 30 to 40 percent of the magnesium the foods contain.

But it’s worth noting that other research has found that people who took also a dietary supplement along with magnesium from food got more than an adequate amount, suggesting that supplements may be helpful if you’re not getting enough through food alone.

Who Should Consider Taking a Supplement?

Knowing if you’re deficient in magnesium is a tough task. “We can’t detect deficiency from a blood test, except in extreme clinical cases,” explains Jenna Volpe, RDN, a functional registered dietitian nutritionist and founder of Whole-istic Living in Austin, Texas. 
That’s because less than 1 percent of the magnesium in your body is in your blood.

Still, there are clues that you’re not getting enough magnesium from your diet. Signs that you’re running low on magnesium include: 

• Constipation
• Fatigue
• Muscle cramps
• Anxiety or depression
• Restless legs syndrome
• Headaches

While it’s best to turn to food for your magnesium needs, many of us could probably benefit from supplementing a modest amount, Dr. Jampolis says. 

Health conditions like type 2 diabetes and inflammatory bowel disease and medications like diuretics and treatments for acid reflux (heartburn) can deplete your magnesium or increase the amount you need, Jampolis says. Older adults and those with alcohol use disorder also tend to have low magnesium intakes. 

If you fall into any of these categories or notice symptoms of a deficiency, talk to your doctor about supplementing with magnesium.

What Dose of Magnesium Supplement Should You Take?

When shopping for a magnesium supplement, you’ll see that products offer doses ranging from 200 to 500 mg. Most people can benefit from taking 200 to 300 mg per day, notes Taylor Wallace, PhD, food scientist and CEO of Think Healthy Group, a food science and nutrition consulting firm in Washington, DC. 
Jampolis cautions against taking higher doses, unless your medical provider specifically recommends it. Typically, the kidneys eliminate excess magnesium from food in the urine. But in some cases, high doses of supplements can cause diarrhea, nausea, and abdominal cramping. (The maximum daily amount of magnesium that adults can tolerate without adverse effects is 350 mg.)

Magnesium plays a vital role in numerous bodily functions, from muscle relaxation to energy production.

What Time of Day Is Best to Take Magnesium Supplements? And 4 More FAQs

1. What Time of Day Is Best to Take Magnesium Supplements? 

When you take magnesium isn’t as critical as watching what you take with it. “Other nutrients can interfere with the absorption of magnesium,” Dr. Wallace explains. 

In particular, calcium and iron compete with magnesium for absorption. So, if you’re taking supplemental calcium or iron, take these supplements at separate times of the day, says Wallace. 

One exception is if you’re getting these nutrients in a multivitamin. Your body can absorb about 500 to 600 mg of calcium without interfering with magnesium, Wallace says. If your formula has, for instance, 200 mg of calcium in it (as many multivitamins do), you should be okay.

2. Are There Risks or Side Effects Associated With Taking Magnesium Supplements?

For the most part, magnesium supplements are safe. However, if you take more than your body can handle, magnesium can cause digestive side effects, including diarrhea and stomach pain, Wallace says.

3. Should You a Take Magnesium Supplement With Food or Can You Take It on an Empty Stomach?

It’s best to take a magnesium supplement with food. Taking it on an empty stomach can increase your risk of gastrointestinal side effects like diarrhea.

4. Should Anyone Avoid Taking Magnesium Supplements?

TRENDING: Newly Legalized Herb Relieves Pain - Available Without A Prescription

Magnesium supplements are generally safe. However, talk to your doctor before taking a magnesium supplement if you have heart disease or kidney disease, Jampolis says. In addition, magnesium supplements can interact with certain medications, including bisphosphonates (used to treat osteoporosis), antibiotics, diuretics, and proton pump inhibitors (used to treat acid reflux or stomach ulcers).

If you take any of these medications, speak with your healthcare provider before supplementing with magnesium.

5. How Do You Know If You’re Taking Too Much Magnesium?

If you exceed the amount of magnesium your body can handle, you’ll know, says Wallace. “Where people go wrong is taking megadoses. If you take too much, you’ll have stomach pain and diarrhea,” he says. The NIH recommends limiting your magnesium intake to 350 mg per day (for adults), unless your doctor says otherwise.

The Takeaway

The recommended daily allowance of magnesium ranges from 310 to 429 mg, depending on age, sex, and pregnancy or breastfeeding status. Magnesium is vital for many essential bodily functions, including nerve and muscle relaxation, blood glucose control, heart rhythm, and bone health, but nearly half of all U.S. adults may not be getting enough through their diets alone. 

Symptoms of magnesium deficiency include fatigue, muscle cramps, constipation, restless legs syndrome, headaches, and anxiety or depression. The best sources of magnesium are dietary, including leafy green vegetables, nuts, whole grains, and legumes. Consult a healthcare professional if you think you may have magnesium deficiency and would benefit from a supplement, especially if you live with a health condition like diabetes that can affect absorption.