This calculator adjusts serum calcium levels based on albumin concentration, helping healthcare professionals interpret calcium values more accurately in patients with hypoalbuminemia or hyperalbuminemia.
Learn how to use the Adjusted Calcium Calculator and understand its clinical significance
Use this calculator when interpreting serum calcium levels in patients with abnormal albumin levels. Albumin levels can significantly affect measured calcium levels, as calcium binds to albumin in the blood.
The calculator uses the following formula to adjust calcium based on albumin:
Adjusted Calcium (mg/dL) = Total Calcium (mg/dL) + 0.8 × (4 - Serum Albumin (g/dL))
This formula adds back approximately 0.8 mg/dL of calcium for each 1 g/dL that the serum albumin is below 4 g/dL. Conversely, it subtracts 0.8 mg/dL if the albumin is above 4 g/dL.
Measured calcium levels can be misleading in patients with hypoalbuminemia (low albumin) or hyperalbuminemia (high albumin). Adjusting calcium levels helps to more accurately assess the patient's calcium status and guide clinical decisions.
Consider a patient with the following values:
Adjusted Calcium = 8.5 + 0.8 × (4 - 3.2) = 8.5 + 0.8 × 0.8 = 9.26 mg/dL
This adjustment would change a seemingly normal calcium level to one that might be considered low, prompting further investigation.