Dairy products are the major source of dietary calcium. Eggs, green leafy
vegetables, broccoli, legumes, nuts, and whole grains provide smaller amounts.
Only about 10% to 30% of the calcium in foods is actually absorbed in the body.
Calcium is absorbed in the small intestine. Absorption is influenced by the
amount of vitamin D available and the levels of calcium already present in
the body.
HypercalcemiaHypercalcemia is a condition when the serum calcium level is higher than
10.5 mg/dL indicating there is a higher than normal concentration of calcium.
This usually produces a low serum phosphorus level.
Hypercalcemia can be caused by:
- Renal failure.
- Immobility.
- Cancer.
- Hyperparathyroidism.
- Excess intake of calcium supplements (such as in Tums and other medica-
tions to prevent and treat osteoporosis). - Overuse of antacids for GI disturbances.
- Prolonged diarrhea.
- Excessive use of diuretics.
The nurse should be alert to identify the following signs and symptoms
of hypercalcemia:
- Patients with mild hypercalcemia may have no signs and symptoms
- Nausea,
- Vomiting,
- Constipation,
- Anorexia,
- Abdominal pain,
- Polyuria (frequent urination),
- Polydipsia (extreme thirst),
- Decreased memory,
- Personality changes or mood swings,
- Confusion,
- Depressed reflexes,
- Muscular weakness,
CHAPTER 10 Fluid and Electrolyte Therapy^173