The headline “Health experts issue a new warning about magnesium supplements” needs some context. Magnesium is an essential mineral, and getting it from food is generally safe. The main concerns are with high-dose supplements, medication interactions, and certain medical conditions. Office of Dietary Supplements
The two groups that deserve particular caution
- People with impaired kidney function
Healthy kidneys remove excess magnesium. When kidney function is significantly reduced, magnesium from supplements or magnesium-containing laxatives/antacids can accumulate and, at very high levels, cause low blood pressure, weakness, difficulty breathing, abnormal heart rhythm and potentially cardiac arrest. Office of Dietary SupplementsIf you have kidney disease or an abnormal creatinine/eGFR, don’t start a high-dose magnesium supplement without your clinician’s advice.
- People taking medications that interact with magnesium
Magnesium can interfere with absorption of certain antibiotics and bisphosphonates used for osteoporosis. Diuretics can also alter magnesium levels. Long-term proton-pump inhibitors can lower magnesium levels themselves. Office of Dietary Supplements
How much is too much?
For adults, the U.S. NIH sets an upper limit of 350 mg per day of magnesium from supplements and medications (not magnesium naturally present in food), unless a healthcare professional recommends otherwise. Excess supplemental magnesium commonly causes diarrhea, nausea and abdominal cramping; very high amounts can be dangerous. Office of Dietary Supplements
At 83, it’s especially sensible to check your medications and kidney function before taking a concentrated magnesium supplement. Older adults are also among the groups more likely to have inadequate magnesium intake, so this doesn’t mean you should avoid magnesium altogether. Office of Dietary Supplements
If you tell me the magnesium dose/type you’re considering and your current medicines, I can check the specific combination for you.
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