Calculate an albumin-adjusted magnesium estimate and review broad magnesium context with a cautious educational worksheet.
The Corrected Magnesium Calculator applies an albumin-adjustment estimate to total serum magnesium so the measured value can be reviewed in the context of low albumin. Because serum magnesium reflects only a small fraction of total body magnesium, and because albumin-adjusted magnesium is not as standardized as albumin-adjusted calcium, this page should be read as a cautious worksheet rather than a definitive diagnostic model.
The output combines the measured magnesium, an albumin-adjusted estimate, broad reference bands, and a rough body-store estimate. That makes it useful for educational review and quick context, but it does not replace direct clinical interpretation, serial lab review, ECG findings, or renal-function assessment.
Low albumin can complicate the interpretation of total magnesium. This page keeps the adjustment transparent so the measured value, the albumin-adjusted estimate, and the broad severity bands can be reviewed side by side instead of treated as a single black-box number.
Albumin-adjusted Mg estimate (mg/dL) = Measured Mg + 0.005 × (40 − Albumin in g/L) Where Albumin in g/L = Albumin in g/dL × 10 Unit Conversion: 1 mmol/L Mg = 2.43 mg/dL Reference Range: 1.7–2.2 mg/dL (0.70–0.91 mmol/L) Rough body-store estimate (mEq) ≈ (1.9 − Adjusted Mg) × Weight(kg) × 0.3 These adjustment and deficit formulas are approximations for educational review, not validated replacement protocols.
Result: Corrected Mg = 1.88 mg/dL — Normal
Measured Mg is 1.8 mg/dL, albumin is 2.5 g/dL (25 g/L). Correction: 1.8 + 0.005 × (40 − 25) = 1.8 + 0.075 = 1.875. With significant hypoalbuminemia, the corrected value is slightly higher but still within the normal range.
Magnesium is the fourth most abundant cation in the body and the second most abundant intracellular cation after potassium. It is a cofactor for over 300 enzymatic reactions including ATP synthesis, DNA replication, protein synthesis, and neuromuscular function. Only 1% of total body magnesium is in the serum, making blood levels a poor indicator of total body stores.
Hypomagnesemia causes neuromuscular irritability (tremors, tetany, seizures), cardiac arrhythmias (prolonged QT, torsades de pointes, atrial and ventricular arrhythmias), and electrolyte disturbances (refractory hypokalemia and hypocalcemia). Chronic deficiency is associated with type 2 diabetes, hypertension, cardiovascular disease, osteoporosis, and migraine headaches.
Always interpret magnesium alongside potassium, calcium, and phosphate levels. In diabetic ketoacidosis, total body magnesium can be depleted even if serum levels appear normal because hemoconcentration may mask the deficit. As treatment and fluid are given, magnesium may fall further, which is why the broader clinical picture matters more than the worksheet alone.
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This page calculates an albumin-adjusted estimate from measured total magnesium and albumin, then places the value beside broad magnesium reference bands and a rough body-store estimate. It is included as a cautious interpretation worksheet because serum magnesium reflects only a small fraction of total body magnesium and albumin-adjusted magnesium is not a uniformly standardized clinical measure.
The output is not a validated replacement protocol, and it should not be used to prescribe IV or oral magnesium by itself. Symptoms, ECG changes, renal function, calcium or potassium abnormalities, and repeat labs matter more than the worksheet alone.
A portion of serum magnesium is protein-bound, so low albumin can complicate interpretation of the measured total magnesium. The adjustment shown here is meant as a cautious estimate rather than a universally accepted clinical standard.
Common causes include chronic alcohol use, poor intake, GI losses such as diarrhea or vomiting, renal wasting from diuretics, proton pump inhibitor use, diabetic ketoacidosis, pancreatitis, and some medications such as cisplatin, amphotericin B, and calcineurin inhibitors.
No. The page is not a dosing or infusion protocol. Replacement decisions depend on symptoms, ECG findings, renal function, route of administration, concomitant electrolyte abnormalities, and the treatment setting.
Different magnesium salts have different tolerability and bioavailability, but this page does not rank products or prescribe a replacement regimen. That choice should be individualized to the clinical situation.
Yes. Hypermagnesemia (> 2.6 mg/dL) causes hypotension, bradycardia, decreased deep tendon reflexes, and at very high levels (> 7 mg/dL), respiratory depression and cardiac arrest. It typically occurs with renal failure combined with magnesium supplementation.
Ionized magnesium is conceptually closer to the biologically active fraction, but testing is less available and not uniformly standardized. That is one reason this page should be treated as an estimate worksheet rather than as a definitive magnesium-status standard.