Calcium Supplements and Hypercalcemia

• Many clients take calcium supplements for hypocalcemia or risk of deficiency.
• Those at risk include adolescents, pregnant/breastfeeding/postmenopausal women, and those with lactose intolerance or osteoporosis risk.
• Calcium carbonate is a primary component of antacids for gastric hyperacidity.
• Calcium supplements are classified as mineral and electrolyte supplements.

Prototype Medications

• Calcium citrate: used primarily for calcium replacement as a dietary supplement.
• Calcium carbonate: used as a calcium supplement and primarily as an antacid.

Pharmacologic Action

• Calcium supplements provide a non-dietary source of calcium.
• Calcium neutralizes gastric acid.
• Vitamin D enhances calcium absorption from the intestine.

Adverse Reactions

• Long-term use of calcium supplements/antacids with Vitamin D may lead to hypercalcemia.
• Hypercalcemia symptoms: nausea/vomiting, constipation, polyuria, and depression.
• Hypercalcemia may cause renal calculi (kidney stones) and hypercalciuria.

Interventions

• Periodically check serum calcium levels.
• Monitor for decreased gastric/intestinal motility: nausea, vomiting, constipation.
• Monitor for urine output exceeding intake, flank pain, or blood in urine.

Administration

• Can be given orally or intravenously.
• Give calcium supplements 1 hr before or 1-2 hr after glucocorticoids, thyroid supplements, tetracycline, and quinolone antibiotics.
• Give calcium-based antacids 1 hr after meals with a full glass of water, and again at bedtime.

Client Instructions

• Report hypercalcemia manifestations: nausea/vomiting, increased urination, depression.
• Prevent constipation by eating a high-fiber diet, increasing water intake, and using laxatives if needed.
• Consider fiber supplements or stool softeners.
• Report flank pain or blood in urine.
• Take calcium 1 hr before or 1-2 hr after certain medications.
• Take calcium-based antacids one hour after meals and at bedtime.
• Chew the tablet, swallow with water, and don't exceed 600 mg at once.
• Calcium citrate has higher bioavailability than calcium carbonate
• Chewable calcium preparations also increase bioavailability.

Contraindications

• Hypercalcemia and low phosphate levels.
• History of kidney stones and cardiac dysrhythmias.
• Use with caution in clients who have slow gastric motility.

Interactions

• Hypercalcemia from calcium supplements may increase digoxin toxicity risk.
• Glucocorticoids decrease calcium absorption; avoid concurrent use.
• Calcium supplements decrease absorption of thyroid hormones, tetracycline, and quinolone antibiotics.
• Thiazide diuretics with calcium supplements increase hypercalcemia risk due to decreased calcium excretion.
• Foods like cereals, rhubarb, and spinach decrease calcium absorption.

Multiple Choice Questions and Answers

• Medications effective in both disease prevention and treatment of osteoporosis: Raloxifene, Alendronate
• Indications of hypercalcemia: Nausea

• Mimics the effects of estrogen on the bones: Raloxifene
• Reduces the number of osteoclasts: Alendronate
• Raises calcium levels: Calcitonin salmon
• Increased the excretion of calcium: Thiazide diuretics

Clients often use calcium supplements for hypocalcemia or deficiency risks, including adolescents and pregnant women. Calcium carbonate is an antacid component and supplements are mineral/electrolyte replacements. Adverse reactions from long-term use with Vitamin D include hypercalcemia and renal calculi.