Magnesium (Mg)

What is magnesium?

Magnesium is an essential mineral that we need to keep our muscles functioning and our bones strong. Magnesium is considered a macromineral because it’s required in relatively large quantities in the body. Since we can’t produce magnesium, we must get this mineral through our diet.

Why we need it

There are over 300 enzymatic reactions in the body that require magnesium.¹ These reactions are involved in energy production, gene expression, cell growth and division, cell signaling, and nutrient metabolism, among other things.¹

Magnesium is also critical for bone health. Magnesium promotes the formation of new bone, and it helps protect against bone breakdown.² Not surprisingly, the majority of the body’s magnesium is found in bone.²

Magnesium has many other miscellaneous functions. It protects against inflammation, and it helps us produce hormones and growth factors. It’s also important for blood clot formation, blood pressure regulation, and electrolyte balance, among other processes.¹

Where it’s found

Magnesium is found in a wide variety of foods, including both animal and plant foods. Examples of magnesium-rich foods include:

Leafy greens
Nuts and seeds
Breakfast cereal
Fish and seafood
Legumes
Edamame
Peas
Potato
Cocoa

Magnesium can also be taken as a supplement. It’s available in many different forms, including magnesium citrate, magnesium lactate, magnesium oxide, and magnesium chloride.³

Daily requirements

The daily Recommended Dietary Allowance (RDA) for magnesium, or the daily amount that is likely to meet the needs of most healthy people, is 80 milligrams (mg) for children aged 1-3 years; 130 mg for children aged 4-8 years; 240 mg for adolescents aged 9-13 years; 410 mg for males aged 14-18 year; 360 mg for females aged 14-18 years; 400 mg for men aged 19-30 years; 310 mg for women aged 19-30 years; 420 mg for men over the age of 31; and 320 mg for women over the age of 31. For pregnant women, the recommended amount increases by 40 mg a day.

Magnesium deficiency

Magnesium deficiency can have many consequences on our health. It can impair muscle function, causing symptoms like cramping, tremors, and seizures.¹ Magnesium deficiency may also cause us to become deficient in other nutrients, such as calcium.¹ It can also increase our risk of high blood pressure, bone issues, and chronic diseases like heart disease and diabetes.²

Groups that may be at higher risk for magnesium deficiency include people with alcoholism, older adults, and people with malabsorptive disorders.³

Can you get too much magnesium?

Magnesium from food has not been found to cause any adverse effects. Excessive magnesium supplementation, on the other hand, has been reported to cause negative side effects like nausea, vomiting, fatigue, and low heart rate.¹ Magnesium toxicity (from supplements) may be fatal in severe cases.¹

A Tolerable Upper Intake Level (UL), or a maximum daily amount that is considered safe, has been established for magnesium. The UL for magnesium is 65 mg for children aged 1-3 years, 110 mg for children aged 4-8 years, and 350 mg for anyone over the age of 9 years.³ These values refer only to magnesium from supplements, not from food (which is why for some age ranges, the UL is less than the RDA).

Fun facts

Magnesium may help fight stress and anxiety. There is some research to suggest that magnesium supplementation may be effective in treating anxiety.⁴ Nonetheless, further research is needed to clarify the extent of these benefits.

Some types of magnesium supplements are used for other purposes, beyond just correcting or preventing magnesium deficiency. For instance, magnesium citrate is used to treat constipation, and magnesium sulfate (or Epsom salts) is used to relieve muscle soreness or cramping.