Research summary
Magnesium: Essential Mineral and Enzyme Cofactor
Magnesium is an essential dietary mineral that the body uses as a cofactor in more than 300 enzyme systems.[1]
Scope of this definition
This definition describes magnesium’s normal physiological role; it does not evaluate whether a magnesium supplement improves a particular health outcome.[1]
What magnesium does in the body
As an essential dietary mineral, magnesium acts as a cofactor in more than 300 enzyme systems involved in processes such as energy production, protein synthesis, and normal muscle and nerve function.[1]
How do food requirements differ from supplement limits?
The adult recommended intake covers magnesium from all sources: 310–420 mg daily for nonpregnant adults, depending on age and sex. The adult upper limit of 350 mg concerns magnesium from supplements and medications, excluding magnesium naturally present in food and beverages. These numbers have different denominators, so they are not contradictory targets and should not be added together as a dosing plan.[1]
Leafy vegetables, legumes, nuts, seeds, and whole grains contribute magnesium without requiring a supplement choice. When reading a Supplement Facts panel, use its elemental-magnesium amount. That amount can be compared with intake references; the weight of citrate or another entire compound is a different measurement. Dietary reference values are not doses proven to treat sleep, migraine, or anxiety.[1]
References
- Magnesium - Health Professional Fact Sheet. NIH Office of Dietary Supplements. Retrieved 2026-06-18. Government health fact sheet View source →
Read the concise FAQ answer
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How much magnesium should you take?
For nonpregnant adults, the magnesium RDA ranges from 310 to 420 mg per day from all sources depending on age and sex; pregnancy and lactation use separate age-specific reference values. The adult 350 mg per day upper limit is different: it applies only to magnesium from dietary supplements and medications. On a supplement label, compare these references with the elemental magnesium amount in Supplement Facts, not the weight of the whole magnesium compound.
Read FAQ →What does magnesium do in the body?
Magnesium is an essential mineral used in hundreds of enzyme systems. It supports energy production, protein synthesis, normal muscle and nerve function, blood glucose and blood pressure regulation, bone structure, and normal heart rhythm.
Read FAQ →