1. People With Kidney Problems
This is perhaps the most important consideration.
Healthy kidneys help remove excess magnesium from the body through urine. But when kidney function is impaired, the body may have more difficulty getting rid of excess magnesium.
That means magnesium from supplements or certain medications can potentially build up in the bloodstream.
According to the NIH, the risk of magnesium toxicity increases when kidney function is impaired or when kidney failure is present.
For that reason, people with kidney disease should not simply start taking a high-dose magnesium supplement because they have heard that magnesium is beneficial.
A doctor or pharmacist can determine whether supplementation is appropriate and, if so, what amount is suitable.
2. People Taking Certain Medications
The second group includes people who regularly take medications that can interact with magnesium.
Magnesium can interfere with the absorption of certain medicines when they’re taken too close together.
For example, magnesium can reduce the absorption of some oral bisphosphonates, which are used to treat osteoporosis. It can also interact with certain antibiotics, including tetracyclines and quinolone antibiotics.
Some medications can also affect magnesium levels themselves.
Diuretics, for example, may increase or decrease magnesium loss through the urine depending on the type of medication. Long-term use of certain proton pump inhibitors can also contribute to low magnesium levels.
That’s why it’s important to tell your doctor or pharmacist about supplements you’re taking—not just prescription medicines.
