How is corrected calcium calculated?

The calculation for corrected calcium is crucial in clinical settings, particularly in cases of hypoalbuminemia, where low albumin levels can lead to falsely low measurements of total serum calcium. The correct approach involves adjusting the measured calcium value based on the patient’s albumin level.

Corrected calcium is specifically calculated to interpret the calcium level accurately in relation to the albumin concentration. The formula used involves adding 0.8 to the measured calcium for every 1 g/dL that albumin is below the normal level of 4 g/dL. Therefore, the correct calculation reflects this adjustment:

Corrected Calcium = Measured Calcium + 0.8 (4 - Albumin)

This formula takes into account the fact that calcium binding to albumin decreases as albumin levels drop, thereby necessitating a correction to accurately assess calcium status in the presence of low albumin.

Thus, option B correctly describes the calculation method, providing a reliable way to adjust measured calcium to reflect true physiological calcium levels.