Medically Reviewed by Zilpah Sheikh, MD on May 19, 2024
5 min read

Magnesium is a mineral that's crucial for the body's functions. 

What does magnesium do for the body?

Magnesium helps keep blood pressure normal, bones strong, and the heart rhythm steady. It also controls your blood sugar levels and makes protein and DNA.

Magnesium deficiency

When you don't get enough magnesium over time, you can end up with a deficiency. You may not feel it right away because your body tries to hold on to what little magnesium it has in your pee. Some illnesses and medicines can also mess with how your body handles magnesium, making deficiency more likely. Signs of a magnesium deficiency include:

  • Not feeling hungry
  • Feeling sick
  • Throwing up
  • Being tired
  • Feeling weak

If you're really low on magnesium, you might feel numb and tingly, get muscle cramps, have seizures, or changes to your heart rhythm. Some people are more likely to have a magnesium deficiency. They include:

  • People with gut problems such as Crohn's or celiac disease
  • People with type 2 diabetes
  • People who misuse alcohol over a long period
  • Older adults
  • People who have parathyroid problems
  • People who take certain drugs for diabetes and cancer
  • People with kidney disease

Health care providers sometimes suggest that people with these conditions take magnesium supplements.

Proton pump inhibitors (PPIs), a common type of medicine used to treat acid reflux, are also linked to low magnesium levels. Examples of PPIs include:

If you take any of these medicines for a long time, your health care provider may perform a blood test to check your magnesium level.

Experts say that many people in the U.S. aren't eating enough foods with magnesium. Adults who get less than the recommended amount of magnesium are more likely to have high levels of inflammation markers. Inflammation has been associated with major health conditions such as heart disease, diabetes, and certain cancers. Also, low magnesium appears to be a risk factor for osteoporosis.

There's some evidence that eating foods high in magnesium and other minerals can help prevent high blood pressure in people with prehypertension.

Doctors prescribe intravenous or injected magnesium to treat other conditions, such as eclampsia during pregnancy and severe asthma attacks. Magnesium is also the main ingredient in many antacids and laxatives.

Magnesium for anxiety

Research shows magnesium could help you handle stress better and keep your cortisol levels in check. When your body doesn't have enough magnesium, stress can hit you harder. And when you're under a lot of physical or mental pressure, your magnesium levels can drop. The mineral may also calm your brain's chemical messengers, helping you feel more relaxed and ease muscle tension and cramps.

Magnesium for migraines

Researchers have found that magnesium deficiency could play a role in migraine attacks. They're looking at whether magnesium supplements or IV treatments could ease symptoms.

Magnesium and sleep

Magnesium might improve sleep by controlling a brain chemical called GABA, which is crucial for sleep. It can also help relax muscles and regulate your nervous system, which could mean you'll sleep better at night.

Does magnesium help you lose weight?

Magnesium supplements have shown promise in lowering body mass index (BMI), especially in people with magnesium deficiency and obesity. This indicates that the mineral may help reduce overall body fat.

The recommended dietary allowance (RDA) includes the magnesium you get from both the food you eat and any supplements you take.


Recommended Dietary Allowance (RDA)


1-3 years

80 milligrams/day

4-8 years

130 milligrams/day

9-13 years

240 milligrams/day


14-18 years

360 milligrams/day

19-30 years

310 milligrams/day

31 years and over

320 milligrams/day


Under 19 years: 400 milligrams/day
19 to 30 years: 350 milligrams/day
31 years and up: 360 milligrams/day


Under 19 years: 360 milligrams/day
19 to 30 years: 310 milligrams/day
31 years and up: 320 milligrams/day


14-18 years

410 milligrams/day

19-30 years

400 milligrams/day

31 years and up

420 milligrams/day

Recommended magnesium intake for children

1-3 years: 80 milligrams/day
4-8 years: 130 milligrams/day
9-13 years: 240 milligrams/day
14-18 years: 360 milligrams/day

Recommended magnesium intake during pregnancy

Under 19 years: 400 milligrams/day
19-30 years: 350 milligrams/day
31 years and up: 360 milligrams/day

Recommended magnesium intake while breastfeeding

Under 19 years: 360 milligrams/day
19-30 years: 310 milligrams/day
31 years and up: 320 milligrams/day

Most people get more than enough magnesium from foods and do not need to take magnesium supplements, as too much of the mineral can be toxic. In addition to what you get from food, the highest dose you should take of magnesium supplements is:

  • 65 milligrams/day for children aged 1-3
  • 110 milligrams/day for children aged 4-8
  • 350 milligrams/day for adults and children aged 9 or older

These doses are the highest anyone should add to their diet. Many people take in significant quantities of magnesium through the foods they eat. It's safe to get high levels of magnesium naturally from food, but adding large amounts of supplements to your diet can prove dangerous. Do not exceed these maximum advised levels.

Natural food sources of magnesium include:

  • Green, leafy vegetables such as spinach
  • Nuts
  • Seeds
  • Beans, peas, and soybeans
  • Whole-grain cereals
  • Wheat germ
  • Wheat
  • Oat bran

Eating whole foods is always best. Magnesium can be lost during refinement and processing.

Taking magnesium may cause side effects and other problems. Here's a closer look at some of them:

Magnesium side effects

Magnesium supplements can cause nausea, cramps, and diarrhea. Magnesium supplements often cause softening of stool.

Magnesium interactions

Magnesium supplements may interact with certain medicines, including diuretics, heart medicines, or antibiotics. If you take any medicine, check with your health care provider before taking magnesium.

Conditions with extra risk factors

People with diabetes, intestinal disease, heart disease, or kidney disease should not take magnesium before speaking with their health care provider.

Magnesium overdose

Signs of a magnesium overdose can include nausea, diarrhea, low blood pressure, muscle weakness, and fatigue. At very high doses, magnesium can be fatal.

Magnesium is a mineral vital for normal blood pressure, strong bones, and steady heart rhythms. Many Americans don't get enough magnesium in their diets, which can lead to health issues such as inflammation, osteoporosis, and high blood pressure. While doctors suggest magnesium supplements for people with certain health conditions or taking specific medications, too much of the mineral can be harmful. Natural sources of magnesium include green leafy vegetables, nuts, beans, and whole-grain cereals.