Magnesium plays many important roles in the body, so marketers advertise magnesium supplements for a wide variety of uses. Should you buy in?
Needs vs. Intake. “Scientific surveys suggest the average dietary magnesium intake in the U.S. is somewhat under the recommended amount,” says Bess Dawson-Hughes, MD, an endocrinologist at Tufts Medical Center. However, this underconsumption of magnesium is not necessarily a risk to health. In healthy people, the kidneys regulate how much magnesium is excreted in the urine to keep blood levels relatively constant. When magnesium deficiency does occur, it is typically in people with absorptive disorders such as Crohn’s or celiac disease, long-term alcoholism, or uncontrolled type 2 diabetes (as high blood sugar levels can cause the kidneys to excrete more magnesium). Severe magnesium deficiency is rare.
Health Effects. A dietary pattern that provides the recommended amount of magnesium is associated with a number of health benefits.
Cardiovascular disease: Dietary patterns rich in magnesium are associated with lower risk of heart disease and stroke, but it’s hard to determine how much of this effect is attributable to magnesium alone. Foods high in magnesium are also typically high in other minerals, vitamins, and fiber, which contribute to the cardiovascular benefits.
Type 2 diabetes: Consuming a magnesium-rich dietary pattern is also associated with lower risk of developing type 2 diabetes. This association could easily be related to the magnesium-rich foods being a hallmark of healthy dietary patterns. There is no evidence to date that magnesium supplements can help prevent or treat type 2 diabetes.
Osteoporosis: “Compared to diets low in magnesium, higher magnesium intake has been associated with higher bone mineral density in observational studies and in clinical trials,” says Dawson-Hughes. “This is important in reducing the risk of osteoporosis and bone fractures.” More research is needed to determine if magnesium supplements can help prevent or treat osteoporosis.
Migraines: Some (but not all) people who suffer from migraine headaches have been found to have low blood levels of magnesium. A handful of small studies suggest magnesium supplements may modestly reduce migraine frequency, although we do not have enough information to know if they can help reduce risk or ease symptoms. If you get migraines, it is recommended you do not start supplements without the approval of your healthcare provider.
Safety First. Too much magnesium can cause diarrhea, nausea, and abdominal cramping. Extremely high intakes can lead to irregular heartbeat and even cause the heart to stop beating. You cannot get too much magnesium through dietary consumption, but adding supplements to your diet could cause you to overdo it. It’s recommended that magnesium from supplements and magnesium-containing medications (like some laxatives and antacids) be limited to no more than 350 milligrams (mg) a day.
➧ Eat Well. If you regularly eat foods like veggies, nuts, seeds, beans, leafy greens, and yogurt, it is highly likely you get enough magnesium.
➧ Watch the Research. There is yet to be any proof that magnesium supplements benefit health (unless someone is deficient due to an underlying illness).
➧ Be Aware of Dangers. Too much magnesium from supplements can lead to adverse effects.
What to Do. “Food sources are the best option to boost magnesium intake,” says Dawson-Hughes. “Supplementation is a distant second to food as an approach to boosting magnesium intake, as far as health is concerned.”
Magnesium-rich foods form the basis of a healthy dietary pattern. Aim to include them throughout the day. See “Foods High in Magnesium” for some top dietary sources.