Medically reviewed on March 25, 2018
(KAL see um SIT rate)
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Capsule, Oral [preservative free]:
Cal-Citrate: 150 mg [dye free]
Generic: 760 mg/3.5 g (480 g)
Generic: 250 mg, 1040 mg
Tablet, Oral [preservative free]:
Calcitrate: 950 mg [lactose free, milk derivatives/products, no artificial color(s), no artificial flavor(s), sodium free, soy free, sugar free, wheat free, yeast free]
Generic: 200 mg
Brand Names: U.S.
- Cal-Citrate [OTC]
- Calcitrate [OTC]
- Calcium Salt
Moderates nerve and muscle performance via action potential excitation threshold regulation
25% to 35%, requires vitamin D; varies with age (infants 60%, prepubertal children 28%, pubertal children 34%, young adults 25%); decreased absorption occurs in patients with achlorhydria, renal osteodystrophy, steatorrhea, or uremia
Primarily in the feces as unabsorbed calcium
Use: Labeled Indications
Dietary supplement: Use as a dietary supplement when calcium intake may be inadequate
OTC labeling: Dietary supplementation: Oral: 200 mg to 4 g (as elemental calcium) daily in 1 to 3 divided doses
May administer with or without food; administration with food may increase absorption.
Dietary reference intake for calcium (IOM 2011):
0 to <6 months: Adequate intake: 200 mg elemental calcium daily
6 to 12 months: Adequate intake: 260 mg elemental calcium daily
1 to 3 years: RDA: 700 mg elemental calcium daily
4 to 8 years: RDA: 1,000 mg elemental calcium daily
9 to 18 years: RDA: 1,300 mg elemental calcium daily
19 to 50 years: RDA: 1,000 mg elemental calcium daily
Females ≥51 years: RDA: 1,200 mg elemental calcium daily
Males: 51 to 70 years: RDA: 1,000 mg elemental calcium daily; >70 years: RDA: 1,200 mg elemental calcium daily
Pregnancy/Lactating: RDA: Requirements are the same as in nonpregnant or nonlactating females
Store at room temperature.
Alpha-Lipoic Acid: Calcium Salts may decrease the absorption of Alpha-Lipoic Acid. Alpha-Lipoic Acid may decrease the absorption of Calcium Salts. Consider therapy modification
Aluminum Hydroxide: Citric Acid Derivatives may increase the absorption of Aluminum Hydroxide. Monitor therapy
Bictegravir: Calcium Salts may decrease the serum concentration of Bictegravir. Management: Bictegravir, emtricitabine, and tenofovir alafenamide can be administered with calcium salts under fed conditions, but coadministration with or 2 hours after a caclium salt is not recommended under fasting conditions. Consider therapy modification
Bisphosphonate Derivatives: Calcium Salts may decrease the serum concentration of Bisphosphonate Derivatives. Management: Avoid administration of oral calcium supplements within: 2 hours before or after tiludronate/clodronate/etidronate; 60 minutes after oral ibandronate; or 30 minutes after alendronate/risedronate. Exceptions: Pamidronate; Zoledronic Acid. Consider therapy modification
Calcium Acetate: Calcium Salts may enhance the adverse/toxic effect of Calcium Acetate. Avoid combination
Calcium Channel Blockers: Calcium Salts may diminish the therapeutic effect of Calcium Channel Blockers. Monitor therapy
Cardiac Glycosides: Calcium Salts may enhance the arrhythmogenic effect of Cardiac Glycosides. Monitor therapy
Deferiprone: Calcium Salts may decrease the serum concentration of Deferiprone. Management: Separate administration of deferiprone and oral medications or supplements that contain polyvalent cations by at least 4 hours. Consider therapy modification
DOBUTamine: Calcium Salts may diminish the therapeutic effect of DOBUTamine. Monitor therapy
Dolutegravir: Calcium Salts may decrease the serum concentration of Dolutegravir. Management: Administer dolutegravir at least 2 hours before or 6 hours after oral calcium. Administer dolutegravir/rilpivirine at least 4 hours before or 6 hours after oral calcium salts. Alternatively, dolutegravir and oral calcium can be taken together with food. Consider therapy modification
Eltrombopag: Calcium Salts may decrease the serum concentration of Eltrombopag. Management: Administer eltrombopag at least 2 hours before or 4 hours after oral administration of any calcium-containing product. Consider therapy modification
Estramustine: Calcium Salts may decrease the absorption of Estramustine. Consider therapy modification
Multivitamins/Fluoride (with ADE): May increase the serum concentration of Calcium Salts. Calcium Salts may decrease the serum concentration of Multivitamins/Fluoride (with ADE). More specifically, calcium salts may impair the absorption of fluoride. Management: Avoid eating or drinking dairy products or consuming vitamins or supplements with calcium salts one hour before or after of the administration of fluoride. Consider therapy modification
Multivitamins/Minerals (with ADEK, Folate, Iron): May increase the serum concentration of Calcium Salts. Monitor therapy
Phosphate Supplements: Calcium Salts may decrease the absorption of Phosphate Supplements. Management: This applies only to oral phosphate and calcium administration. Administering oral phosphate supplements as far apart from the administration of an oral calcium salt as possible may be able to minimize the significance of the interaction. Exceptions: Sodium Glycerophosphate Pentahydrate. Consider therapy modification
Quinolones: Calcium Salts may decrease the absorption of Quinolones. Of concern only with oral administration of both agents. Exceptions: LevoFLOXacin (Oral Inhalation); Moxifloxacin (Systemic). Consider therapy modification
Strontium Ranelate: Calcium Salts may decrease the serum concentration of Strontium Ranelate. Management: Separate administration of strontium ranelate and oral calcium salts by at least 2 hours in order to minimize this interaction. Consider therapy modification
Tetracyclines: Calcium Salts may decrease the serum concentration of Tetracyclines. Management: If coadministration of oral calcium with oral tetracyclines can not be avoided, consider separating administration of each agent by several hours. Consider therapy modification
Thiazide and Thiazide-Like Diuretics: May decrease the excretion of Calcium Salts. Continued concomitant use can also result in metabolic alkalosis. Monitor therapy
Thyroid Products: Calcium Salts may diminish the therapeutic effect of Thyroid Products. Management: Separate the doses of the thyroid product and the oral calcium supplement by at least 4 hours. Consider therapy modification
Trientine: Calcium Salts may decrease the serum concentration of Trientine. Trientine may decrease the serum concentration of Calcium Salts. Consider therapy modification
Vitamin D Analogs: Calcium Salts may enhance the adverse/toxic effect of Vitamin D Analogs. Monitor therapy
Frequency not defined. Mild hypercalcemia (calcium: >10.5 mg/dL) may be asymptomatic or manifest as anorexia, constipation, nausea, and vomiting. More severe hypercalcemia (calcium: >12 mg/dL) is associated with coma, confusion, delirium, and stupor.
Central nervous system: Headache
Endocrine & metabolic: Hypercalcemia, hypophosphatemia, increased thirst
Gastrointestinal: Abdominal pain, anorexia, constipation, nausea, vomiting
Concerns related to adverse effects:
• Gastrointestinal effects: Constipation, bloating, and gas are common with calcium supplements (especially carbonate salt).
• Achlorhydria: Calcium absorption is impaired in achlorhydria; common in elderly. Citrate may be preferred because better absorbed.
• Hypoparathyroid disease: Hypercalcemia and hypercalciuria are most likely to occur in hypoparathyroid patients receiving high doses of vitamin D.
• Kidney stones (calcium-containing): Use caution when administering calcium supplements to patients with a history of kidney stones.
• Renal impairment: Use with caution in patients with renal failure to avoid hypercalcemia; frequent monitoring of serum calcium and phosphorus is necessary.
Concurrent drug therapy issues:
• Minerals/other oral drugs: Calcium administration interferes with absorption of some minerals and drugs; use with caution.
• Vitamin D: It is recommended to concomitantly administer vitamin D for optimal calcium absorption.
• Absorption: Taking calcium (≤500 mg) with food improves absorption.
• Appropriate product selection: Multiple salt forms of calcium exist; close attention must be paid to the salt form when ordering and administering calcium; incorrect selection or substitution of one salt for another without proper dosage adjustment may result in serious over or under dosing.
Monitor plasma calcium levels if using calcium salts as electrolyte supplements for deficiency.
Calcium crosses the placenta. Intestinal absorption of calcium increases during pregnancy. The amount of calcium reaching the fetus is determined by maternal physiological changes. Calcium requirements are the same in pregnant and nonpregnant females (IOM, 2011).
• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
• Patient may experience constipation, nausea, vomiting, abdominal pain, or lack of appetite. Have patient report immediately to prescriber mood changes or signs of high calcium (weakness, confusion, fatigue, headache, nausea and vomiting, constipation, or bone pain) (HCAHPS).
• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.
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