What is the corrected calcium level formula?

The formula for corrected calcium levels, specifically when adjusting for low albumin levels, is designed to provide a more accurate reflection of a person's calcium status in the presence of hypoalbuminemia. The correct calculation involves taking the measured calcium level and adjusting it based on the deficit of albumin compared to a normal value, which is usually considered to be 4 g/dL.

Option B outlines this process accurately by adding the product of 0.8 and the difference between the normal albumin level (4 g/dL) and the measured albumin level. This method effectively adjusts the calcium level upward to account for the lower availability of binding proteins (such as albumin) that normally bind to calcium in the bloodstream. This adjustment is crucial because total calcium levels can appear artificially low when albumin levels are low, leading to a misleading clinical interpretation.

The other options do not incorporate the concept of adjusting for the normal albumin level compared to the patient's albumin level in the same way. Thus, they do not provide the accurate corrected calcium level needed for clinical assessments in the context of altered albumin levels, which makes the formula presented in option B the most suitable for this situation.