Most (98%) of the body's calcium is stored in the teeth and bones. In the blood, about half the calcium is bound to plasma proteins, and about half is free (ionized, Ca++).
Calcium levels may rise in the presence of:
Cancer
Acidosis
Hyperthyroidism
Hyperparathyroidism
Bedrest
Calcium supplements
Excessive vitamin D intake
Calcium levels may fall in the presence of:
Decreased plasma proteins
Alkalosis
Diarrhea
Vitamin C deficiency
Normal Values*
Men
8.8–10.0 mg/dL
2.15–2.55 mmol/L
Women
9.0–10.5 mg/dL
2.15–2.55 mmol/L
Pregnancy
8.1–9.5 mg/dL
2.02–2.40 mmol/L
Children
9.2–11.0 mg/dL
2.30–2.75 mmol/L
*These are general values taken from a variety of sources. The actual normal values may vary from lab to lab and from one type of testing protocol to another.