Magnesium is an essential nutrient. It helps your muscles and nerves function properly and helps your bone health and development. Would a magnesium supplement be a good choice for you?
Dawn Gerber, PharmD, a clinical ambulatory pharmacy specialist with Banner Health, said men need 400 mg to 420 mg of magnesium per day, while women need 310 mg to 320 mg daily. In most instances, you can get the magnesium you need from a healthy, balanced diet. “Most people do not need a magnesium supplement to meet the recommended daily amount. Following a well-balanced meal plan that you enjoy should be enough,” she said.
Spinach and other green leafy vegetables, nuts, seeds, legumes, beans, plain yogurt, milk and whole grains are magnesium-rich foods. You’ll find magnesium added to some breakfast cereals and oatmeal as well. Highly processed foods are less likely to have the magnesium you need.
Here’s when a magnesium supplement might make sense
Some people with certain health conditions might need more magnesium than they get in their diets. You might want to consider a magnesium supplement if you:
- Have long-term alcoholism and alcohol dependence, since your diet may be poor
- Have osteoporosis, since you need more magnesium to help protect your bones
- Have Crohn’s disease or celiac disease, since chronic diarrhea may lower your levels of magnesium over time
- Have uncontrolled type 2 diabetes, since high blood sugar levels can make you urinate more, and that can remove magnesium from your body
- Are older, since as you age, your gut tends to absorb less magnesium from food, and your kidneys get rid of more magnesium
Dr. Gerber points out the claims that magnesium can help lower blood pressure are unfounded. “Studies show that the effects of magnesium on high blood pressure are minimal and insignificant. No one should rely on magnesium supplements for lowering blood pressure,” she said.
Can you get too much magnesium?
Even if you get slightly more than the recommended amount of magnesium in your diet, it’s usually not a problem—your kidneys will eliminate the excess. But taking high doses (more than 350 mg per day in magnesium supplements) can cause side effects such as diarrhea, nausea and stomach cramps.
And be careful if you take laxatives. Some laxatives (including magnesium citrate) contain magnesium and consuming more than 5,000 milligrams per day of magnesium from these laxatives can lead to magnesium toxicity. Symptoms include low blood pressure, nausea, vomiting, an inability to urinate, muscle weakness and even the inability to breathe. If you have kidney issues you should be especially careful to avoid magnesium toxicity.
Here’s how to pick a good magnesium supplement
If you choose to take a dietary supplement, pick one that’s been evaluated for quality and safety. Dr. Gerber recommends looking for one of these four certifications:
And ask your doctor or pharmacist to run a drug interaction check before you start taking a magnesium supplement, since magnesium can interact with diuretics (water pills), bisphosphonates, medications used to treat acid reflux and zinc supplements. Magnesium can also make it less likely you absorb antibiotics properly, so the antibiotic could lose its ability to treat your infection.
The bottom line
You should be able to get the magnesium you need with a healthy diet but some people with certain health conditions can have magnesium deficiencies. If you choose to supplement your magnesium intake, make sure you take a safe dose, choose a brand that’s been evaluated and talk to your pharmacist or doctor about possible interactions. Connect with a Banner Health dietitian or primary care provider for more help reviewing your diet.
These articles can help you learn more about the link between nutrition and your health: