{"id":"magnesium-rbc","name":"Magnesium, RBC","shortName":"RBC Magnesium","aliases":["RBC Magnesium","Erythrocyte Magnesium","Magnesium, Red Blood Cell","Mg RBC","Magnesium, Erythrocytes","Magnesio eritrocitario","Magnesium, Red Blood Cells","Magnesium RBC","RBC Mg","Red Cell Magnesium","Red Blood Cell Magnesium"],"abbreviations":["RBC Mg","Mg RBC"],"loinc":[{"code":"26746-8","primary":true},{"code":"2597-3","primary":false}],"specimen":"red-blood-cells","units":[{"ucum":"mg/dL","display":"mg/dL"},{"ucum":"mmol/L","display":"mmol/L"}],"referenceRanges":[{"population":"Adults","low":3.7,"high":7,"unit":"mg/dL","unitDisplay":"mg/dL","note":"Labcorp prints 3.7–7.0 mg/dL (about 1.52–2.88 mmol/L), with no age or sex split on its test page. RBC magnesium is not standardized across labs, so other labs print different ranges. How well red-cell magnesium reflects total body magnesium is uncertain (NIH Office of Dietary Supplements; Workinger 2018), so being outside the range does not by itself show a deficiency. The causes listed for a low or high result follow the Merck Manual's causes of low and high serum magnesium, and whether they carry over to red-cell magnesium is not established. Use the range printed on your own report first.","sources":[{"title":"Magnesium, RBC (test 080283)","url":"https://www.labcorp.com/tests/080283/magnesium-rbc","publisher":"Labcorp"},{"title":"Magnesium, RBC (test 080283), sample patient report","url":"https://files.labcorp.com/testmenu-d8/sample_reports/080283.pdf","publisher":"Labcorp","year":2024},{"title":"Magnesium: Fact Sheet for Health Professionals","url":"https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/","publisher":"NIH Office of Dietary Supplements"},{"title":"Challenges in the Diagnosis of Magnesium Status","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC6163803/","publisher":"Nutrients","year":2018},{"title":"Hypomagnesemia","url":"https://www.merckmanuals.com/professional/nephrology/electrolyte-disorders/hypomagnesemia","publisher":"Merck Manual Professional Version"},{"title":"Hypermagnesemia","url":"https://www.merckmanuals.com/professional/nephrology/electrolyte-disorders/hypermagnesemia","publisher":"Merck Manual Professional Version"}]}],"review":{"status":"ai-draft","label":"AI-drafted. Awaiting verification","lastReviewed":"2026-10-03"},"summary":"Magnesium measured inside your red blood cells. Some clinicians use it to look at magnesium stores, but how well it reflects your whole-body magnesium is debated.","url":"https://bloodtesttracker.com/markers/magnesium-rbc","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}