1. What is Corrected Calcium?

The corrected calcium calculation adjusts the measured calcium level for hypoalbuminemia, providing a more accurate assessment of biologically active calcium in the blood.

2. How Does the Calculator Work?

The calculator uses the corrected calcium equation:

Where:

• Calcium — Measured serum calcium (mg/dL)
• Albumin — Serum albumin level (g/dL)
• 4 — Normal albumin level (g/dL)
• 0.8 — Correction factor

Explanation: The equation accounts for the fact that about 40-45% of serum calcium is bound to albumin, so low albumin levels can falsely lower total calcium measurements.

3. Importance of Calcium Correction

Details: Corrected calcium is particularly important in patients with hypoalbuminemia (low albumin levels) to avoid missing cases of true hypercalcemia or hypocalcemia.

4. Using the Calculator

Tips: Enter calcium in mg/dL and albumin in g/dL. Both values must be valid (calcium > 0, albumin ≥ 0).

5. Frequently Asked Questions (FAQ)

Q1: When should calcium be corrected for albumin?
A: Always when albumin is abnormal, especially in critically ill patients or those with chronic diseases affecting albumin levels.

Q2: What are normal calcium values?
A: Normal total calcium is typically 8.5-10.2 mg/dL (may vary by lab). Corrected calcium should fall within this range in healthy individuals.

Q3: Are there alternative correction formulas?
A: Some labs use slightly different formulas (e.g., Payne's formula: corrected Ca = Ca + (0.02 × (40 - albumin in g/L))), but this 0.8 × (4 - albumin) is most common.

Q4: Does this work for hyperalbuminemia?
A: The formula can be used when albumin is high, but clinical significance of corrected calcium in hyperalbuminemia is less clear.

Q5: Should ionized calcium be measured instead?
A: In critical situations or when albumin is extremely abnormal, direct measurement of ionized calcium may be more accurate.