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Corrected Calcium Calculator

Corrected Calcium

Understanding Corrected Calcium

Corrected calcium is an adjusted calcium value that takes into account the effect of albumin levels on total serum calcium. This calculation is important because calcium in blood exists in two main forms - protein-bound (primarily to albumin) and ionized calcium - in roughly equal proportions. When albumin levels are abnormal, the total calcium measurement may not accurately reflect the physiologically active (ionized) calcium level.

Why Calculate Corrected Calcium?

Total serum calcium can be misleading when albumin levels are abnormal:

  • Low albumin falsely lowers total calcium without affecting ionized calcium
  • High albumin falsely elevates total calcium without affecting ionized calcium
  • Corrected calcium provides a better estimate of the physiologically active calcium

Important Limitations

This calculator:

  • Should not be used in patients with nephrotic syndrome
  • May not be accurate if laboratory methods differ significantly from standard methods
  • Is less reliable than direct ionized calcium measurement in critical situations
  • Assumes normal acid-base status

Normal Ranges

  • Corrected Calcium:
    • 8.5-10.5 mg/dL
    • 2.12-2.62 mmol/L

Clinical Significance

Low Corrected Calcium (Hypocalcemia)

May indicate:

  • Vitamin D deficiency
  • Hypoparathyroidism
  • Chronic kidney disease
  • Magnesium deficiency
  • Certain medications

High Corrected Calcium (Hypercalcemia)

May indicate:

  • Hyperparathyroidism
  • Malignancy
  • Sarcoidosis
  • Vitamin D toxicity
  • Certain medications

When to Check Corrected Calcium

  • When albumin levels are abnormal
  • Monitoring calcium disorders
  • Evaluating symptoms of calcium imbalance
  • Following parathyroid conditions
  • Monitoring certain medications

Clinical Applications

Corrected calcium is particularly useful in:

  • Hospital settings
  • Critical care
  • Outpatient monitoring
  • Endocrine disorders
  • Kidney disease
  • Suspected hyperparathyroidism
  • Older adults with unexplained symptoms

Start calculating now to better understand your calcium status!

References:

  1. Payne RB, et al. Interpretation of serum calcium in patients with abnormal serum proteins. Br Med J. 1973;4(5893):643-646.