1. What is Corrected Calcium?

Corrected calcium is an adjusted calcium value that accounts for variations in albumin levels. Since approximately 50% of calcium in the blood is bound to albumin, changes in albumin levels can affect total calcium measurements without reflecting true changes in ionized calcium.

2. How Does the Calculator Work?

The calculator uses the corrected calcium formula:

Where:

• \( \text{Ca} \) — Total serum calcium (mg/dL)
• \( \text{Alb} \) — Serum albumin (g/dL)
• 4 — Normal albumin level (g/dL)
• 0.8 — Correction factor (mg/dL calcium per g/dL albumin)

Explanation: The formula adjusts the measured calcium level to what it would be if the albumin level were normal (4 g/dL).

3. Importance of Calcium Correction

Details: Corrected calcium provides a more accurate assessment of calcium status in patients with abnormal albumin levels, helping clinicians distinguish between true hypocalcemia/hypercalcemia and apparent changes due to albumin variations.

4. Using the Calculator

Tips: Enter total serum calcium in mg/dL and serum albumin in g/dL. Both values must be positive numbers for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: When should calcium correction be used?
A: Correction should be applied when albumin levels are abnormal (typically <3.5 g/dL or >4.5 g/dL) to get a more accurate assessment of calcium status.

Q2: What is the normal range for corrected calcium?
A: Normal corrected calcium is typically 8.5-10.5 mg/dL, similar to total calcium reference ranges.

Q3: Are there limitations to this correction formula?
A: The formula provides an estimate and may not be accurate in all clinical situations, particularly with severe hypoalbuminemia or acid-base disorders.

Q4: Should ionized calcium be measured instead?
A: In critical situations or when precise calcium assessment is needed, direct measurement of ionized calcium is preferred as it reflects the physiologically active form.

Q5: Does this formula work with SI units?
A: This specific formula is designed for mg/dL and g/dL units. For mmol/L units, different correction factors apply.