Calcium (Ca+)

Calcium (Ca+) is a cation absorbed into the bloodstream from dietary sources and functions in bone formation, nerve impulse transmission, and contraction of myocardial and skeletal muscles. Calcium aids in blood clotting by converting prothrombin to thrombin.

Normal Lab Value for Calcium

  • Total: 4.5 – 5.5 mEq/L (8.5 to 10.5 mg/dL)
  • Ionized: 2.5 mEq/L (4.0 – 5.0 mg/dL) 56% of total calcium

Nursing Considerations

  • Instruct the client to eat a diet with a normal calcium level (800 mg/day) for 3 days before the exam.
  • Instruct the client that fasting may be required for 8 hours before the test.
  • Note that calcium levels can be affected by decreased protein levels and the use of anticonvulsant medications