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Magnesium is an essential mineral involved in many important functions in the body, but magnesium supplements are not appropriate for everyone. Certain medications can interact with magnesium, while some medical conditions may increase the risk of complications.
If you regularly take prescription or over-the-counter medicines, it is important to check with a doctor or pharmacist before starting a magnesium supplement.
Medications That May Interact With Magnesium
Magnesium can interfere with the absorption of some medicines when taken at the same time. Examples include certain antibiotics, thyroid medications such as levothyroxine, and some medicines used to treat osteoporosis.
For these medications, healthcare professionals may recommend separating the doses by several hours. The exact timing depends on the specific medicine.
Magnesium may also interact with certain other medications or supplements, so don’t assume that a product is safe simply because it is sold without a prescription.
People With Kidney Problems Should Be Especially Careful
The kidneys help remove excess magnesium from the body. People with significantly reduced kidney function may be at greater risk of magnesium accumulating in the bloodstream.
If you have kidney disease or have been told that your kidney function is reduced, speak with a healthcare professional before taking magnesium supplements or magnesium-containing laxatives.
More Magnesium Isn’t Always Better
Magnesium supplements can cause side effects, particularly at higher doses. Diarrhea, nausea, and abdominal cramping are among the more common problems.
It is also important to distinguish between magnesium obtained naturally from foods and high-dose magnesium supplements. Foods such as nuts, seeds, legumes, whole grains, and leafy green vegetables can provide magnesium as part of a balanced diet.
Check Before Starting a Supplement
Before taking magnesium, make a list of all prescription medicines, over-the-counter medicines, vitamins, and supplements you use. A pharmacist or doctor can check whether magnesium is appropriate and whether you need to separate it from another medication.
Bottom line: Don’t automatically avoid magnesium altogether. Instead, check for medication interactions and medical conditions that could make supplementation unsafe.