1. What is Albumin Adjusted Calcium?

Albumin adjusted calcium is a calculated value that estimates what the serum calcium level would be if the albumin level were normal. Since approximately 40-45% of serum calcium 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 formula:

Where:

• \( Ca \) — Measured serum calcium (mmol/L)
• \( Normal\ Alb \) — Reference albumin level (typically 40 g/L)
• \( Alb \) — Measured serum albumin (g/L)
• \( 0.2 \) — Adjustment factor (mmol/L per g/L of albumin)

Explanation: For every 1 g/L that albumin is below normal, the calcium decreases by approximately 0.2 mmol/L. This formula adjusts for this relationship.

3. Importance of Calcium Adjustment

Details: Correcting calcium for albumin levels is crucial for accurate assessment of calcium status, particularly in patients with abnormal albumin levels due to malnutrition, liver disease, nephrotic syndrome, or other conditions affecting protein metabolism.

4. Using the Calculator

Tips: Enter measured calcium in mmol/L, reference albumin (typically 40 g/L), and measured albumin in g/L. All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: When should I use albumin adjusted calcium?
A: Use this calculation when albumin levels are abnormal (typically <35 g/L or >45 g/L) to get a more accurate assessment of calcium status.

Q2: What is the normal range for adjusted calcium?
A: The normal range is typically 2.20-2.60 mmol/L, similar to total calcium, but consult your laboratory's reference range.

Q3: Why is the adjustment factor 0.2?
A: Research has shown that for each 1 g/L change in albumin, calcium changes by approximately 0.2 mmol/L in the opposite direction.

Q4: Are there limitations to this calculation?
A: This formula provides an estimate. For precise assessment, especially in critical situations, directly measured ionized calcium is preferred.

Q5: Does this work with different units?
A: This calculator uses mmol/L for calcium and g/L for albumin. Convert units if necessary (1 mg/dL calcium = 0.25 mmol/L; 1 g/dL albumin = 10 g/L).