If you’re asking about the “new alert” behind this headline, the important point is that magnesium supplements are not dangerous for
most healthy people when used appropriately. The concern is mainly excessive supplemental magnesium and people whose bodies cannot clear it efficiently.
The 2 groups that need particular caution
1. People with kidney disease
This is the most important group.
Your kidneys remove excess magnesium from the blood. When kidney function is significantly reduced, magnesium can accumulate, potentially causing hypermagnesemia (abnormally high blood magnesium). In severe cases, this can lead to weakness, low blood pressure, abnormal heart rhythms, confusion, breathing problems, and other serious effects. PubMed Central (PMC)+1
That doesn’t mean everyone with chronic kidney disease can never receive magnesium. Research suggests magnesium can sometimes be used in people with CKD under medical supervision. The important distinction is self-prescribing a supplement versus having magnesium monitored by a healthcare professional. PubMed Central (PMC)
2. People taking high doses of magnesium supplements
Even people with healthy kidneys can experience problems when taking large amounts. The most common effects are diarrhea, nausea, abdominal discomfort, and gastrointestinal irritation. Mayo Clinic MC Press+1
In the U.S., the established tolerable upper intake level for magnesium from supplements and medications is 350 mg/day for adults; this limit doesn’t include magnesium naturally present in food. The 350-mg figure is based primarily on gastrointestinal effects, and there is ongoing debate about whether that limit should be revised. ScienceDirect
What about older adults?
Older age itself isn’t a reason to avoid magnesium. However, kidney function tends to decline with age, and changes in magnesium absorption and handling can occur. PubMed Central (PMC)+1
So an older person—particularly someone with reduced kidney function or taking multiple medications—shouldn’t automatically assume that a high-dose magnesium supplement is harmless.
Food is different from supplements
Magnesium-rich foods include:
- Nuts and seeds
- Beans and lentils
- Whole grains
- Dark leafy vegetables
- Some fish
- Certain fruits
For most people, getting magnesium through food is preferable to taking a supplement unnecessarily. Mayo Clinic similarly recommends focusing on magnesium-rich foods first and discussing supplementation with a healthcare professional if you’re concerned about your intake. Primary Care in Rochester and Kasson
Bottom line
Magnesium is an essential mineral, not something people generally need to fear. The biggest warning is against taking high-dose supplements without considering kidney function, medications, and whether supplementation is actually needed.
If you have kidney disease, are older with reduced kidney function, or take several medications, it’s especially sensible to check with your doctor or pharmacist before starting magnesium. Mayo Clinic MC Press
If you tell me which magnesium you’re considering (glycinate, citrate, oxide, etc.) and the dose on the bottle, I can explain whether that particular product and dose is reasonable.
