What it means
The most common mineral in the body; almost all of it is in the bones and teeth. The small amount in the blood is vital for muscle contraction, nerve signals, the heartbeat and blood clotting. The level is controlled by parathyroid hormone, vitamin D and the kidneys. A low level (hypocalcemia) makes nerves and muscles twitchy, with tingling and cramps; a high level (hypercalcemia) causes weakness, constipation and confusion.
For the nurse
A low albumin level makes the total calcium read low, so it is often interpreted with albumin. Watch clients after thyroid or parathyroid surgery for tingling around the mouth and muscle spasms. Teach calcium and vitamin D for bone health.
In a chart
"Calcium 7.6 mg/dL; client reports tingling around the mouth."
At a glance
| Normal range | Total calcium 9.0–10.5 mg/dL [2.25–2.62 mmol/L] |
|---|---|
| Critical range | Below 6.0 or above 13.0 mg/dL [below 1.5 or above 3.25 mmol/L]; each lab sets its own critical values. |
| Abbreviations | Ca; Ca2+ (calcium ion) |
| Spanish | calcio |
| Also written | calcium level, serum calcium, total calcium, calcium levels |
Related terms
potassium
A mineral in the blood that nerves and muscles, including the heart, need in order to work.
electrolyte
A mineral that carries an electric charge when dissolved in body fluids, such as sodium, potassium, calcium and chloride.
osteoporosis
A condition in which bones lose density and become thin, weak and easy to break.
sodium
A mineral in the blood that controls how water moves in the body and helps nerves and muscles work.