Know Your Nutrient: Magnesium

Magnesium is a mineral that acts as a cofactor in over 300 essential metabolic reactions, such as protein synthesis, blood glucose control, muscle and nerve function, and blood pressure. Additionally, magnesium is involved in the transportation of calcium and potassium ions, which is crucial for normal cardiac rhythm and muscle contraction.^1,2 

About 60% of magnesium stores are located in the skeleton, while <1% are in extracellular fluids, including blood.¹ Normal serum levels of magnesium range from 0.76 to 1.15 mmol/L.² The recommended dietary allowances for magnesium are as follows:³

• Children aged 1–3 years: 80 mg
• Children aged 4–8 years: 130 mg
• Adolescents aged 9–13 years: 240 mg
• Female individuals aged 14–18 years: 360 mg
• Male individuals aged 14–18 years: 410 mg
• Female individuals aged 19–30 years: 310 mg
• Male individuals aged 19–30 years: 400 mg
• Female individuals aged ≥31 years: 320 mg
• Male individuals aged ≥31 years: 420 mg
• Foods high in magnesium include:³
• Pumpkin seeds: 156 mg per 1 oz
• Chia seeds: 111 mg per 1 oz
• Almonds: 80mg per 1 oz
• Spinach (boiled): 78 mg per 1/2 cup
• Cashews: 74 mg per 1 oz
• Shredded wheat: 61 mg per 2 large biscuits
• Soymilk: 61 mg per 1 cup
• Black beans (cooked): 60 mg per 1/2 cup

Deficiency and health impact

Hypomagnesemia, or magnesium deficiency, occurs when serum magnesium level is <0.75 mmol/L. Early symptoms of hypomagnesemia can be nonspecific and overlap with symptoms of other electrolyte abnormalities (eg, hypokalemia [low potassium], hypocalcemia [low calcium]). Symptoms can include nausea, vomiting, loss of appetite, weakness, tremors, muscle spasms and cramps, cardiac arrhythmia, behavioral changes, and seizures, among others.^2,4 Gastrointestinal disorders, malabsorption, renal disease, metabolic or endocrine disorders, and increased renal loss of magnesium can cause hypomagnesemia.^1,2,4 Additionally, the use of certain medications, such as proton pump inhibitors, chemotherapeutic agents, diuretics, and antibiotics can cause hypomagnesemia.^2,4

Given magnesium’s extensive role in the body, hypomagnesemia is associated with various health conditions.

Diabetes. Magnesium is essential for maintaining blood glucose control and normal insulin sensitivity, with low levels linked to insulin resistance. Higher magnesium intake is associated with decreased risk of developing type 2 diabetes.^2,4,5

Cardiovascular diseases. The body depends on magnesium for various cardiovascular-related functions, including cardiac rhythm, blood pressure, and vasodilation (widening of blood vessels). There is an inverse association between magnesium and cardiovascular disease (CVD), with low levels of magnesium linked to increased risk of CVD.^2,4 Research also suggests a link between low magnesium levels and greater risk of cardiovascular mortality.^2,5 Hypomagnesemia is associated with a greater risk of cardiac arrhythmia, stroke,^2,4 and electrocardiogram changes.⁴ Evidence also suggests it might be associated with atrial fibrillation⁴ and atherosclerosis.⁵

Neurological conditions. Patients with migraine tend to have decreased levels of magnesium.^2,4 Low magnesium might contribute to migraine via vasoconstriction (narrowing of blood vessels) and neuronal excitability.⁴ Severe hypomagnesemia can lead to generalized tonic-clonic seizures.^2,4

Immune system. Hypomagnesemia might contribute to immune system dysfunction, which can then lead to inflammation. Furthermore, hypomagnesemia might be associated with greater susceptibility to COVID-19.⁵

As a medication. Magnesium sulfate can be utilized as a medication for acute migraine, acute asthma exacerbations, preeclampsia, and seizures caused by preeclampsia/eclampsia.^2,4

Bottom Line

Magnesium is an essential mineral invovled in many bodily functions and processes. Maintaining adequate magnesium levels is important for health, as hypomagnesemia is linked to a variety of health conditions. 

Sources

1. Rude RK. Magnesium. In: Ross AC, Caballero B, Cousins RJ, Tucker KL, Ziegler TR, eds. Modern Nutrition in Health and Disease. 11th ed. Jones & Bartlett Learning, LLC; 2014:159–175.
2. Gröber U, Schmidt J, Kisters K. Magnesium in prevention and therapy. Nutrients. 2015;7(9):8199–8226.
3. Magnesium – health professional fact sheet. National Institutes of Health Office of Dietary Supplements. Updated 6 Jan 2026. Accessed 10 Mar 2026.  https://ods.od.nih.gov/factsheets/magnesium-healthprofessional/
4. Al Alawi AM, Majoni SW, Falhammar H. Magnesium and human health: perspectives and research directions. Int J Endocrinol. 2018;2018:9041694. 
5. Pethő ÁG, Fülöp T, Orosz P, Tapolyai M. Magnesium is a vital ion in the body—it is time to consider its supplementation on a routine basis. Clin Pract. 2024;14(2):521–535.