Quick Answer
Magnesium is a mineral involved in hundreds of processes in the body, including muscle and nerve function, blood sugar control, blood pressure and bone health. Many adults eat less magnesium than recommended, though true deficiency is less common. Supplements can help some people, but they can cause diarrhea at higher doses and may not be safe for people with kidney disease. Food sources come first, and a provider can help decide whether a supplement makes sense.
Who this is for: adults curious about magnesium supplements, or those with conditions or medications that may lower magnesium.
What Magnesium Does
Magnesium helps the body make protein, build bone, control muscle and nerve function, regulate blood sugar and blood pressure, and produce energy.[1] Most of the body’s magnesium is stored in bones and soft tissues, with only a small amount in the blood.
Good food sources include leafy greens, nuts, seeds, beans, whole grains, avocados and dark chocolate.
Who May Be Low in Magnesium
Many people get less magnesium than recommended from food, but serious deficiency is uncommon in healthy people. Low levels are more likely with:[1]
- Type 2 diabetes, especially when poorly controlled
- Digestive conditions, such as Crohn’s disease or celiac disease, or chronic diarrhea
- Long-term alcohol use
- Older age
- Some medications, including long-term acid-reducing medications called proton pump inhibitors and certain diuretics
Signs of low magnesium can include muscle cramps, weakness, fatigue, nausea and, in more serious cases, abnormal heart rhythms. Because most magnesium is stored outside the blood, a blood test does not always reflect total body levels.
Food sources of magnesium include greens, nuts, seeds and beans.
What Supplements Can and Cannot Do
Magnesium supplements are popular for sleep, muscle cramps, constipation and stress. Evidence for these uses is mixed and depends on the condition and the person. Supplements are most clearly helpful for people with a confirmed deficiency or a medical reason to need more.
Magnesium comes in several forms, such as citrate, glycinate and oxide. They differ in how well they are absorbed and how likely they are to cause loose stools.
Safety and Side Effects
Magnesium from food is not a concern, because the kidneys remove the extra. Supplements are different. The recommended upper limit for supplemental magnesium in adults is 350 mg per day, and higher amounts often cause diarrhea, nausea and cramping.[1]
People with kidney disease are at risk of magnesium building up to dangerous levels and should not take supplements without medical guidance. Magnesium can also interact with some medications, including certain antibiotics, osteoporosis medications and diuretics, so timing and dose matter.[2]
How We Approach Supplements at Lake Forest Regenesis
Allana looks at your diet, symptoms, medications and health conditions before recommending magnesium or any other supplement. When a supplement makes sense, she helps choose an appropriate form and dose and checks for interactions with your other medications. For people with kidney disease or complex medication lists, extra caution is taken.
When to See a Provider
Seek urgent care for an irregular or very slow heartbeat, severe weakness, confusion or trouble breathing, especially if you have kidney disease or take high-dose magnesium. Call 911 for chest pain or fainting. Talk with a provider before taking magnesium if you have kidney disease or take prescription medications.
Considering magnesium or another supplement? Allana can review your diet, medications and conditions to help you choose safely.
Frequently Asked Questions
Can magnesium help with sleep?
Some people find it helpful, but research is mixed. Good sleep habits and treating the cause of poor sleep matter more for most people.
Which form of magnesium is best?
It depends on the purpose. Some forms are better absorbed, while others have a stronger laxative effect. Ask your provider which fits your needs.
Can I get enough magnesium from food?
Many people can by eating greens, nuts, seeds, beans and whole grains regularly.
Is magnesium safe with my medications?
It can interact with some antibiotics, osteoporosis medications and diuretics. Check with your provider or pharmacist about timing and dose.
References
- NIH Office of Dietary Supplements. Magnesium: fact sheet for health professionals. Read the fact sheet
- NIH Office of Dietary Supplements. Dietary supplements: what you need to know. Read the fact sheet
This article is for general education and is not a substitute for individual medical advice. See our medical disclaimer.
