Highlights

• Magnesium plays an important and diverse role in our bodies, including supporting the health and function of our bones, heart, muscles and nerves.
• Magnesium is widely available in our food supply: sources include nuts, seeds, legumes, leafy green vegetables, whole grains, dairy, and some fortified foods.
• Research has explored the effect of magnesium on preventing or treating health conditions like hypertension and cardiovascular disease, type 2 diabetes, osteoporosis and migraines; however, the results of this research are inconclusive.

The Basics

Magnesium is one of the most abundant minerals in the human body, residing predominantly in our bones and soft tissue. It’s also naturally found in foods like seeds, nuts, leafy green vegetables, legumes, brown rice, and milk. Magnesium can be added to other food products through the process of fortification, and is also available in dietary supplement form. Additionally, magnesium is an ingredient in certain medications, such as antacids and laxatives.

In the human body, magnesium plays a key role in hundreds of enzymatic reactions that regulate important biological processes, such as influencing muscle and nerve function, stabilizing blood sugar levels, and maintaining blood pressure. Magnesium is also important for the production of metabolic energy, the formation of bone and the synthesis of protein and DNA.

Magnesium and Health

Magnesium has been explored as a treatment or preventative measure for many health conditions— notably, for hypertension and cardiovascular disease, type 2 diabetes, osteoporosis, and migraines. Overall, while observational studies have demonstrated a lower risk of these conditions in people who consume higher amounts of fruits and vegetables, randomized controlled trials (RCTs) have not demonstrated clear therapeutic benefits specific to magnesium (derived from either foods or supplements), especially in people who are generally healthy and consume a varied diet.

• Hypertension and cardiovascular disease: Hypertension (also known as high blood pressure) is a major risk factor for cardiovascular disease and stroke. Some meta-analyses have shown that magnesium supplementation may lower blood pressure—but only to a small degree. Observational studies have found that people with higher dietary magnesium intake have a lower risk of some types of heart disease and stroke. However, it is uncertain whether this result is due to magnesium intake alone or if other confounding variables have influenced the effect.

In early 2022, the U.S. Food and Drug Administration announced that it would allow a qualified health claim on packaged foods regarding magnesium consumption and the potential for reduced risk of hypertension. These health claims must be appropriately worded to avoid misleading consumers; for example, some suggested language advises that “[c]onsuming diets with adequate magnesium may reduce the risk of high blood pressure (hypertension). However, the FDA has concluded that the evidence is inconsistent and inconclusive.”

• Type 2 diabetes: Consuming a diet higher in magnesium has been associated with a lower risk of developing type 2 diabetes. However, more research is needed to explore this connection. The American Diabetes Association notes that there is still insufficient evidence to support the use of magnesium among people with diabetes to improve glycemic control.
• Osteoporosis: Since magnesium plays a role in bone formation, its potential role in osteoporosis prevention and treatment also has been explored. Some population-based studies have examined magnesium-intake levels and bone-mineral density and found positive associations between the two, and other findings show that magnesium deficiency may serve as a risk factor for osteoporosis. While diets containing the recommended amount of magnesium support bone health, randomized controlled trials are needed to directly examine the role of magnesium in the prevention and treatment of osteoporosis.
• Migraines: Some research has shown that magnesium deficiency is tied to factors that promote headaches. However, there is currently limited research on the use of magnesium supplements to prevent or reduce migraine symptoms.

Recommended Intakes

The National Academies of Sciences, Engineering and Medicine have set dietary reference intakes (DRIs) for magnesium. These recommended dietary allowances (RDAs) differ by age, sex (after age 14) and life stage (e.g., pregnancy). There is not enough available research to support an RDA for infants ages 0–12 months, so an Adequate Intake (AI) has been set for that age range based on the average magnesium intake of healthy, breastfed infants, with solid foods added for infants ages 7–12 months.

Table 1. Recommended Dietary Allowances (RDAs) for Magnesium

*Adequate Intake (AI)

Table Source: The Health and Medicine Division of the National Academies of Sciences, Engineering and Medicine

Most Americans do not eat enough of the foods that are good sources of magnesium. Older adults and adolescent boys and girls are most likely not to consume enough magnesium. However, since the amount of magnesium in our body and bloodstream is tightly controlled, it’s uncommon to experience adverse symptoms due to low dietary intake of magnesium. This said, if magnesium intake is chronically low, deficiency symptoms may include appetite loss, nausea, vomiting, and fatigue, and may even progress to muscle cramps, seizures, and abnormal heart rhythms.

Certain groups are at a higher risk for magnesium deficiency, including older adults and people with type 2 diabetes, as well as those with malabsorptive digestive conditions and long-term alcohol dependence. Several types of medications, including certain antibiotics and diuretics, may interact with magnesium supplements or impact magnesium levels in the body. If you are taking any of these medications on a regular basis, be sure to consult a healthcare provider about your magnesium intake.

Tolerable Upper Intake Levels (UL) have been established for magnesium because it is possible to consume too much of it. For many age groups, the UL appears to be lower than the RDA. This difference is because the RDA factors in magnesium from all potential sources of consumption (including food, beverages, supplements, and medications), while the UL includes magnesium derived only from dietary supplements and medications. Overconsumption of magnesium is most common among people who take magnesium supplements or medications that contain magnesium; it is rare among people who consume large quantities of magnesium-containing foods and beverages. High intakes of magnesium from dietary supplements and medications can cause diarrhea, nausea, and abdominal cramping.

Table 2. Tolerable Upper Intake Levels (UL) for Supplemental Magnesium

Table Source: The Health and Medicine Division of the National Academies of Sciences, Engineering and Medicine  

Sources of Magnesium

Magnesium is found in a wide variety of foods, including green leafy vegetables, like spinach, as well as legumes, such as black beans and soy products (including soymilk and edamame). Magnesium is also found in nuts, seeds, whole grains and dairy, including yogurt and milk. Additionally, magnesium is added to some breakfast cereals and other foods through the process of dietary fortification. Finally, magnesium is also available as a dietary supplement.

Magnesium is found in some medications, including laxatives and some medicines used to treat heartburn and upset stomach.

Table 3. Food Sources of Magnesium

Table Source: U.S. Department of Agriculture: Agricultural Research Service. FoodData Central, 2022. 

This article includes contributions from Marisa Paipongna and Ali Webster, PhD, RD.