Calcium is the most abundant cation in the body. The total serum calcium level is the sum of ionized calcium plus complexed calcium and protein-bound calcium.
99% of calcium in the body is in the bones and teeth with the other 1% in circulation. Calcium serves critical functions in nerve conduction, muscle contractility & relaxation, hormone secretion, and blood coagulation.
Hypocalcemia (low Calcium) can clinically present with:
Hypercalcemia (high Calcium) can clinically present with:
The total serum calcium level is clinically useful in:
Additional information:
Consult your laboratory for their normal ranges as these may vary somewhat from the ones listed below.
The serum calcium must be corrected for the blood albumin level. Every decrease in albumin by 1 g/dL (from a value of 4.0 g/dL) requires an adjustment factor of adding 0.8 mg/dL (0.2 mmol/L) to the measure serum calcium. The same correction factor is required for increased albumin levels.
| Conv. Units (mg/dL) | SI Units (mmol/L) | |
|---|---|---|
| Adult | 8.2-10.6 | 2.05-2.65 |
| Children | 8.6-11.2 | 2.15-2.80 |
| Infant | 7.8-11.2 | 1.95-2.80 |
| Newborn | 7.0-12.0 | 1.75-3.00 |
| Critical Values | <6.5 | <1.63 |
| >13 | >3.25 |
Hypercalcemia is the term for elevated blood calcium level. It may be seen in the following conditions:
Drugs that may increase the calcium levels include:
Hypocalcemia is the term for decreased blood calcium level. It may be seen in the following conditions:
Drugs that may cause hypocalcemia include: