9 signs you’re not getting enough magnesium (and what to do about it)

About half of adults in the United States don't get enough magnesium in their daily diet. Considering all the essential functions of magnesium within the body—from aiding in digestion to lowering inflammation—this often overlooked mineral deserves more attention. Magnesium deficiency is an even bigger issue for older adults, especially women.

Why are so many people lacking adequate amounts of magnesium? One potential factor is the industrial processing of grains.

“The evidence shows that magnesium intakes in the United States have significantly declined over the last few generations,” said Lisa Marsh, MS, RD, LD. “Refined whole grains are a likely contributor to this trend since processing wheat to white flour or brown rice to white rice reduces the magnesium content to a significant degree.”

Magnesium deficiency symptoms

So, how can you tell if you’re low on magnesium? Symptoms of magnesium deficiency may include:

• Loss of appetite
• Nausea
• Vomiting
• Fatigue and low energy
• Numbness or tingling
• Muscle cramps
• Seizures
• Personality changes
• Abnormal heart rhythm

If you think you may be experiencing symptoms of magnesium deficiency, talk to your primary care doctor.

Foods high in magnesium

Your body cannot make magnesium by itself, so you need to get it from other places—like your diet. You can get magnesium from the food you eat or by taking a supplement.

What foods have magnesium in them?

• Green leafy vegetables: such as spinach and Swiss chard
• Nuts and seeds: including almonds, pumpkin seeds and chia seeds
• Whole grains: like brown rice and whole wheat bread
• Legumes: beans, lentils and chickpeas are good sources
• Others: avocados, bananas and dark chocolate

“Consuming 100% whole grains, such as brown rice, whole wheat and oats, along with nuts and beans, can ensure higher dietary magnesium intake,” Lisa said.

Here’s a breakdown of the magnesium content in a few of these foods.

• Almond: ½ cup serving has 192 mg magnesium
• Black beans: 1 cup serving has 91 mg magnesium
• Brown rice: 1 cup serving has 84 mg magnesium
• Refined pasta: ½ cup serving has 48 mg magnesium
• Refined white flour: 1 cup serving has 28 mg magnesium
• Whole wheat flour: 1 cup serving has 164 mg magnesium
• Whole wheat pasta: ½ cup serving has 116 mg magnesium
• White rice: 1 cup serving has 19 mg magnesium

Dosages and types of magnesium supplements

Although the recommended intake of magnesium varies based on individual factors, for males, it is recommended to get between 400-420 milligrams of magnesium each day. For females, the recommended amount is between 310-320 milligrams.

Before taking any supplements, it’s always a good idea to discuss this with your doctor. While most people can handle these supplements well, they might not be safe for those who take certain medications.

Supplemental magnesium comes in different forms, and your body can absorb some forms better than others. Forms like magnesium citrate, magnesium aspartate, magnesium lactate and magnesium chloride are usually absorbed well. Talk to your doctor if you have any questions about what kind or amount of magnesium to take.

Are magnesium supplements safe?

Magnesium supplements are usually safe, but it's a good idea to ask your doctor before taking them if you have a medical condition. You probably won't have any problems if you take less than 350 milligrams a day.

But if you have a kidney condition, you might experience more side effects. This is because your kidneys help get rid of any extra magnesium when you pee.

“It is important to note that magnesium in dietary supplements should not be consumed in high amounts, unless recommended by a healthcare provider,” Lisa said. “Excessive intake of magnesium from dietary supplements and medications can cause diarrhea, nausea and abdominal cramping. Extremely high intakes of magnesium can lead to irregular heartbeat and cardiac arrest.”

Taking magnesium supplements can also affect how some medicines work. Here are a few examples:

• If you take osteoporosis medicine called bisphosphonates, it might not work as effectively if you are taking magnesium supplements or other medicines with large amounts of magnesium.
• Antibiotics might not get into your body properly if you take them too close to when you take magnesium supplements.
• Diuretics, which help get rid of extra water in your body, can either make you lose more magnesium or affect how much you lose, depending on the type.
• Medicines for acid reflux or peptic ulcers can make your blood magnesium levels too low if you take them for a long time.
• Taking high doses of zinc supplements can impact how your body absorbs and controls magnesium.

Make sure to let your doctor, pharmacist and other healthcare providers know about any supplements, prescription medicines or over-the-counter medicines you’re taking. They can tell you if the supplements might affect your medicines, or if your medicines might affect how your body uses, absorbs or breaks down nutrients.

Why magnesium is important

Magnesium is critical for many functions throughout your body. It plays a big part in things like exercise, heart health and how your brain works. Fortunately, you can find magnesium in lots of different foods, or you can consider taking a high-quality magnesium supplement to up your intake of this vital mineral.

Before you start taking any new supplements, it's always a good idea to talk to your doctor or healthcare professional first.

Questions about your diet or supplements? Find a dietitian near you.