Dietary supplements may appear harmless, but their combination with medications and other supplements can lead to unexpected outcomes.
Some supplements can worsen existing health issues and alter the effectiveness of prescription drugs and supplements you may already be taking.
Since dietary supplements aren’t regulated by the Food and Drug Administration in the same way as food and medications, they don’t receive FDA approval prior to market release. Consequently, experts advise consulting a healthcare professional before introducing any new supplement into your regimen to avoid potential risks that might only be discovered after purchase and consumption.
Magnesium is among the most widely used supplements, frequently taken to enhance sleep quality. Additionally, it offers benefits for migraines and digestive health, yet it also carries the risk of interacting with other supplements and medications. Here’s what you need to know.
What Is Magnesium?
“Magnesium is an essential mineral,” explains James Fleet, Ph.D., a researcher and expert in nutrition and molecular sciences at the University of Texas at Austin. “It’s a nutrient that must be ingested to fulfill specific physiological requirements.”
This mineral plays a critical role in generating adenosine triphosphate (ATP), a key energy source for cells. According to the Cleveland Clinic, magnesium contributes to over 300 biochemical reactions within the body, maintaining blood pressure, regulating blood sugar, aiding muscle function, facilitating energy generation, and supporting bone health.
Most people receive adequate magnesium from a balanced diet rich in nuts, seeds, beans, grains, and fruits, says Fleet. However, those with certain gastrointestinal disorders may require additional magnesium from supplements.
Like the FDA, the Cleveland Clinic recommends discussing magnesium supplementation with a healthcare provider beforehand.
Excessive magnesium intake can lead to diarrhea, nausea, fatigue, impaired kidney function, and low blood pressure, among various side effects. Magnesium supplements (unlike magnesium from food sources) also pose a higher risk of interactions with medications and other supplements due to their concentrated doses, adds Fleet.
What Is a Drug Interaction?
A drug interaction occurs when a medication’s effects differ due to the presence of another medication or supplement, consumed food or drink, or existing health conditions.
Because of this, healthcare providers should inquire about all medications and supplements you’re taking before recommending new treatment options.
Certain supplements can negatively affect medications, foods, beverages, medical conditions, and other supplements, warns Fleet.
According to the Cleveland Clinic, the impact of these interactions can range from more serious side effects to alterations in medication absorption, ultimately reducing effectiveness.
“A drug interaction is anything that hinders the medication’s intended function, complicating disease management,” explains Fleet.
Healthcare providers prescribe medications based on several factors, including potential interactions with existing treatments. Pharmacists should notify you if anything you’re taking poses a risk of interaction, but they need a comprehensive understanding of your health routine to do so effectively.
Which Drugs and Supplements Interact With Magnesium?
The following are commonly used medications and supplements that may interact with magnesium supplements, according to Fleet. Make sure to consult a healthcare provider to assess your risk of drug interactions.
Antibiotics
- Tetracyclines, a class of antibiotics effective against bacterial infections, are often used for acne, chlamydia, and traveler’s diarrhea, as highlighted by the Cleveland Clinic.
- Fluoroquinolones are also antibiotics, frequently employed in treating complicated bacterial infections, including those that cause urinary tract infections and severe respiratory infections like pneumonia.
Interaction: Magnesium supplements can impede the body’s absorption of these antibiotics, rendering the treatment less effective and leaving the infection unresolved, according to Fleet. In contrast, while antibiotics may decrease magnesium absorption, this concern is relatively minor.
Bone-Loss Medication
- Bisphosphonates are frequently prescribed for conditions such as osteoporosis that affect bone density and strength, as noted by Fleet.
Interaction: “This class of medications is notoriously poorly absorbed under any circumstances,” explains Fleet. For optimal absorption, it’s best to take bisphosphonates with water on an empty stomach. “Taking magnesium simultaneously could severely hinder bisphosphonate absorption,” he adds.
Your doctor may suggest discontinuing magnesium use while taking bisphosphonates or spacing out the two by at least 60 minutes. “Both strategies ensure you receive the full dosage of the medication,” advises Fleet.
Thyroid Medication
- Levothyroxine, a widely used treatment for hypothyroidism and certain cancers, is a synthetic version of the hormone thyroxine, also known as T4, according to the Cleveland Clinic.
Interaction: Synthetic T4 “can directly interact with magnesium in the gastrointestinal tract,” warns Fleet, which might lower the drug’s effectiveness. “To avoid this, ensure a separation of two to four hours between the two substances,” he says.
Calcium Supplements
- Calcium is a vital mineral that contributes to bone health, blood coagulation, and dental wellness, among other functions. Since the body doesn’t produce sufficient calcium, we must obtain it from our diet, as noted by the Cleveland Clinic.
Interaction: Calcium competes with magnesium, particularly when one of the doses is considerably higher, as they exhibit similar chemical structures, warns Fleet. While both may be found in bone health supplements, these combined doses are complementary. However, if you take them separately, a significantly higher magnesium dose—like 2000 milligrams compared to a lower 400-milligram calcium dose—could hinder absorption, Fleet suggests.
Both minerals are absorbed in a similarly comparable manner, meaning they may compete when taken concurrently, diminishing one another’s efficacy. Therefore, it’s advisable to separate the intake of calcium and magnesium by several hours to maximize their benefits.
How to Avoid a Drug Interaction With Magnesium
If you are prescribed medication or taking a supplement that interacts negatively with magnesium, your healthcare provider may recommend several options: stopping magnesium, halting the new supplement or medication, adjusting the dosage, or consuming them at different times of the day, according to Fleet.
Should you concern yourself with potential drug interactions or consider adding magnesium to your health regimen, it is crucial to consult a healthcare provider beforehand.
