Why Correct Calcium?
About 40% of blood calcium is bound to albumin. Measured total calcium includes both bound and free (ionized) calcium. Low albumin falsely lowers total calcium, while high albumin falsely raises it. Correcting for albumin gives a more accurate picture of physiologically active calcium.
Clinical Significance
Ionized calcium (free calcium) is what matters physiologically. Total calcium can be normal while ionized is abnormal if albumin is very low or high. Corrected calcium estimates ionized calcium when direct measurement isn't available. Direct ionized calcium measurement is most accurate but not always available.
Causes of Abnormalities
Hypercalcemia: Hyperparathyroidism, malignancy, vitamin D toxicity, sarcoidosis, thiazide diuretics
Hypocalcemia: Hypoparathyroidism, vitamin D deficiency, chronic kidney disease, hypomagnesemia, acute pancreatitis
Symptoms include muscle cramps, arrhythmias, altered mental status, kidney stones (high), or tetany (low).
Quick Tips
- BMI alone doesn't reflect overall health
- TDEE varies based on activity level
- Consult a healthcare professional for medical decisions
Frequently Asked Questions
When albumin is abnormal (<3.5 or >5 g/dL). Otherwise, total calcium is adequate.
Ionized calcium is more accurate but corrected calcium is a good estimate when ionized isn't available.
Correct the calcium. True calcium status may be normal, high, or low - correction reveals this.
Yes, but consider measuring ionized calcium directly due to complex calcium metabolism in CKD.
High: fatigue, kidney stones, confusion. Low: muscle cramps, tingling, seizures, abnormal heart rhythm.