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Calcium is used by the body to assist in:
  • Blood clotting
  • Muscle contractions
  • Nerve impulse conduction

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 2.152.55 mmol/L
Women 9.010.5 mg/dL 2.152.55 mmol/L
Pregnancy 8.19.5 mg/dL 2.022.40 mmol/L
Children 9.211.0 mg/dL 2.302.75 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.