Test guide
Magnesium Blood Test
A magnesium blood test measures the amount of magnesium in a sample of your blood. Magnesium is a mineral that you get from many kinds of foods you eat. Some examples include nuts, seeds, beans, fortified breakfast cereals, green leafy vegetables, and milk.
What it is for
A magnesium blood test is used to check the level of magnesium in your blood. It's done if your health care provider thinks your levels may not be normal: A magnesium blood test may also be used to help find the cause of abnormal levels of other minerals, including calcium , potassium , and phosphorus. That's because magnesium plays a role in how your body absorbs these minerals. Source: MedlinePlus, National Library of Medicine. Medical test information is public domain. Source identity and definition checked automatically on 2026-10-18. No individual clinical interpretation or human reviewer is asserted.
Limitations
Reference intervals and interpretation depend on the laboratory, specimen, method and clinical context. This source definition is educational information; it does not establish a diagnosis, product approval or suitability for an individual.
Also known as
- Mg, Mag, Magnesium-Serum
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