Magnesium is a mineral that your body needs to regulate blood pressure, stress response, and muscle and nerve function. Taking a magnesium supplement can help you meet your daily needs for this important nutrient and may also improve high blood pressure, ease headaches, and support restful sleep.
Magnesium can be taken at any time of day, with or without food. However, it’s best to avoid taking magnesium supplements with certain foods and drinks, as they may interfere with how well your body absorbs it.
While fiber-rich foods are an excellent choice for overall health, you shouldn’t combine high-fiber foods with magnesium supplements.
“It’s best to avoid foods high in fiber when taking magnesium,” integrative and functional medicine doctor Leigh Erin Connealy, medical director at Center for New Medicine, told Health. “The fiber can bind to magnesium, moving it through the digestive system while preventing it from being absorbed into the bloodstream,” she said.
That said, eating a diet rich in magnesium can usually make up for any reduced absorption caused by higher fiber intake. Nevertheless, it’s best to avoid taking magnesium supplements alongside high-fiber foods to ensure you’re getting the most benefits.
Phytic acid is a compound found in high-fiber foods, like beans and grains.
Foods with high phytic acid include whole grains, legumes (like beans and lentils), and nuts and seeds,” Jobby John, PharmD, the CEO and founder of both Lake Hills Pharmacy and Nimbus Healthcare, told Health. “When you consume it at the same time as your magnesium supplement, the phytic acid essentially ‘grabs onto’ the magnesium, creating an insoluble compound that your body cannot absorb,” he explained.
“Some foods high in phytic acid include nuts and seeds, like almonds, peanuts, chia seeds, and flaxseeds, beans, and whole grains, like brown rice, corn, and quinoa,” said Connealy. “To get the most out of magnesium supplements, wait around two hours between taking magnesium and enjoying these foods.”
Some foods, such as vegetables, like spinach, are high in anti-nutrient compounds called oxalates. Oxalates bind to minerals in your digestive system, making it more difficult for your body to absorb them.
“Similar to phytic acid, oxalic acid can bind with magnesium in the intestines,” John explained. “This forms magnesium oxalate, a compound that isn’t absorbed as well, meaning you get less of the mineral into your system,” he said.
“Foods particularly high in oxalates include spinach, rhubarb, beet greens, and almonds,” Helen Tieu, RD, certified diabetes educator and founder of Diet Redefined, told Health.
Because foods high in oxalates could reduce magnesium absorption, it’s best to avoid consuming these foods close to when you take your magnesium supplement.
Alcohol and caffeine increase the urinary excretion of minerals, like magnesium.
“Excessive alcohol consumption can interfere with magnesium absorption and also increases its excretion by the kidneys, which may lead to deficiencies,” said John.
Excessive alcohol intake can counteract the benefits of magnesium supplementation and can lead to health issues like severe vitamin and mineral deficiencies, liver disease, and more.
Consuming large amounts of caffeine can also reduce the absorption of magnesium in the digestive tract and increase its excretion.
For overall health and to support optimal mineral absorption, it’s best to limit your intake of alcoholic beverages and to avoid drinking high amounts of caffeine.
Soda contains phosphoric acid, a phosphorus-based compound that binds to magnesium and forms compounds that the intestines can’t absorb. This reduces the amount of magnesium available to the body.
Phosphoric acid can also interfere with calcium absorption. Calcium and magnesium are critical for bone health and drinking too much soda can lead to bone issues such as an increased risk of fracture.
To support optimal mineral absorption and overall bone health, it’s best to limit your intake of soda and avoid drinking soda while taking mineral supplements.
Magnesium is primarily absorbed in your small intestine. Certain foods and beverages contain compounds that interfere with how well your body absorbs magnesium.
For example, foods high in fiber, phytic acid, or oxalates, can reduce magnesium absorption, while substances like caffeine and alcohol can increase magnesium excretion through the urine.
The good news is that you can support optimal magnesium absorption and maintain healthy magnesium levels by following a few helpful tips, like taking your magnesium supplement separately from the foods and drinks mentioned above and avoiding excessive intake of alcohol and caffeine.
Magnesium is an essential nutrient that can support overall health. To promote optimal absorption, it’s important to be mindful of what you eat and drink alongside magnesium supplements.
Foods and drinks high in fiber, phytic acid, phosphoric acid, alcohol, and caffeine can interfere with how well your body uses magnesium.
To get the most out of your magnesium supplement, separate it from these foods and drinks whenever possible and pair magnesium supplements with a healthy, balanced diet and lifestyle.
