What is it?
Calcium is a mineral used to treat osteoporosis (bone loss), kidney stones, and menstrual cramps. It is also used as a vitamin supplement to increase bone mass and is used as an antacid (to treat stomach acid upset).
Other names for calcium include: calcium acetate, calcium carbonate, calcium chloride, calcium citrate, calcium gluceptate, calcium gluconate, calcium oxide, calcium salt, and oyster shell calcium.
Ask your doctor, nurse, or pharmacist if you need more information about this medicine or if any information in this leaflet concerns you.
Tell your doctor if you
- are taking medicine or are allergic to any medicine (prescription or over-the-counter (OTC) or dietary supplement)
- are pregnant or plan to become pregnant while using this medicine
- are breastfeeding
- have any other health problems, such as high blood pressure or heart or blood vessel disease
Talk with your caregiver about how much calcium you should take. The amount depends on the strength of the medicine and the reason you are taking calcium. If you are using this medicine without instructions from your caregiver, follow the directions on the medicine bottle. Do not take more medicine or take it more often than the directions tell you to.
To store this medicine:
Keep all medicine locked up and away from children. Store medicine away from heat and direct light. Do not store your medicine in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down and not work the way it should work. Throw away medicine that is out of date or that you do not need. Never share your medicine with others.
Drug and Food Interactions:
Do not take calcium without talking to your doctor first if you are taking:
- Medicines used for osteoporosis (examples: alendronate (Fosamax(R)), etidronate (Didronel(R)), ibandronate (Boniva(R)), risedronate (Actonel(R))) (2,30,35)
- Guar gum (52)
- Heart or blood pressure medications (examples: atenolol (Tenormin(R)), captopril (Capoten(R)), digoxin (Lanoxin(R)), propranolol (Inderal(R)), verapamil (Calan(R), Isoptin(R))) (8,25,26,38)
- Water pills (examples: chlorothiazide (examples: Diurigen(R), Diuril(R)), chlorthalidone (Hygroton(R), Thalitone(R)), hydrochlorothiazide (Esidrix(R), Hydro-Par(R), Microzide(R)), indapamide (Lozol(R)), methyclothiazide (Aquatensen(R), Enduron(R)), metolazone (Mykrox(R), Zaroxolyn(R))) (3,4)
- Medicines used to treat bacterial infections (examples: cefpodoxime (Vantin(R)), cefditoren (Spectracef(R)), ceftriaxone (Rocephin), ciprofloxacin (Cipro(R)), levofloxacin (Levaquin(R)), ofloxacin (Floxin(R)), doxycycline, tetracycline) (12-14,29,34,54)
- Medicines to treat fungal infections (examples: itraconazole (Sporanox(R)), ketoconazole (Nizoral(R))) (16,27,28)
- Medicines to treat human immunodeficiency virus infection (HIV) (examples: amprenavir (Agenerase(R)), fosamprenavir (Lexiva), tipranavir (Aptivus(R))) (31,32,33)
- Medicine used to treat certain stomach and intestinal tract problems (example: hyoscyamine (Cystospaz(R), Levsin(R))) (36)
- Medicine used to treat symptoms of acid reflux disease such as heartburn or ulcer (examples: lansoprazole (Prevacid(R)), sucralfate (Carafate(R))) (37,42)
- Medicine used to treat hyperkalemia (high levels of potassium in the blood) (examples:sodium polystyrene sulfonate Kayexalate(R), Kionex(R), Marlexate(R)) (39,40,41)
- Medicine used to help prevent strokes by keeping blood clots from forming in the blood vessels (example: ticlopidine (Ticlid(R))) (43)
- Medicine used to treat a bone disorder called Paget's disease (example: tiludronate (Skelid(R))) (44)
- Medicine used as a blood thinner, or to treat pain or fever (example: aspirin (Alka-Seltzer(R), Anacin(R), Aspergum(R), Bayer(R), Bufferin(R), Ecotrin(R), Zorprin(R))) (45-48)
- Medicine used as a laxative (example: bisacodyl (Dulcolax(R))) (49)
- Thyroid medicine (examples: Armor Thyroid(R), Synthroid(R), levothyroxine(R)) (5)
- Dietary supplements (iron and zinc) (50, 51)
- Dairy foods, bran, whole cereals, spinach, or rhubarb (A light meal is recommended when you take calcium; however, these should be avoided) (4, 24)
- Medicine used to treat cancer (example: erlotinib (Tarceva(R))) (55)
- Medicine used to treat low blood platelet counts (example: eltrombopag (Promacta(R)) (56)
- Before taking calcium, tell your doctor if you are pregnant or breastfeeding
- Tell your doctor if you have kidney disease or kidney stones (too much calcium may cause kidney stones) (7)
- Make sure your doctor knows if you have an allergy to shellfish (53)
- You should not use certain brands of this medicine if you have kidney disease or are on dialysis. Some brands contain ingredients that could be harmful if your kidneys are not working properly. Always ask your health caregiver what specific brands of this medicine will work best for you (53).
- Some health problems can affect how much calcium you should take. Tell your doctor if you have stomach or digestion problems, such as on-going diarrhea, not absorbing nutrients properly, or not having enough acid in your stomach (53).
- If you are using a large amount of calcium or using it for a long time, your doctor might need to check your blood on a regular basis. Be sure to keep all appointments (53).
Call your doctor right away if you have any of these side effects:
- Allergic reaction: Itching or hives, swelling in your face or hand, swelling or tingling in your mouth or throat, chest tightness, trouble breathing, or rash
Other Side Effects:
You may have the following side effects, but this medicine may also cause other side effects. Tell your doctor if you have side effects that you think are caused by this medicine.
- Headache that will not go away, dry mouth, loss of appetite (53)
- Severe constipation (not able to have a bowel movement) (4, 53)
- Stomach pain, vomiting (can occur if you take too much calcium) (7)
- Stomach upset (more likely to be caused by calcium chloride and calcium gluconate; if stomach problems occur, try calcium lactate (after checking with your doctor or pharmacist) as this may lessen it) (4)
1. Anon: Optimal calcium intake. JAMA 1994; 272:1942-1948.
2. Fleisch H: Bisphosphonates: Pharmacology. Sem Arthritis Rheum 1994; 23:261-262.
3. Gora ML, Seth SK, Bay WK et al: Milk-alkali syndrome associated with use of chlorothiazide and calcium carbonate. Clin Pharm 1989; 8:227-229.
4. Gilman AF, Rall TW, Nies AS et al (eds): Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed. Pergamon Press, New York, NY; 1990.
5. Schneyer CR: Calcium carbonate and reduction of levothyroxine efficacy (letter). JAMA 1998; 33:408-413.
6. Wood RJ & Zheng JJ: High dietary calcium intakes reduce zinc absorption and balance in humans. Am J Clin Nutr 1997; 65:1803-1809.
7. Ivanovitch P, Fellows H & Rich C: The absorption of calcium carbonate. Ann Intern Med 1967; 66:917-923.
8. Dukes MNG: Meyler's side effects of drugs, vol.9. Excerpta Medica, New York, NY; 1980.
9. Shastri RA: Effect of antacids on salicylate kinetics. Int J Clin Pharmacol Ther Toxicol 1985; 23:480-484.
10. Kirch W, Schafer-Korting M, Axthelm T et al: Interaction of atenolol with furosemide and calcium and aluminum salts. Clin Pharmacol Ther 1981; 30:429-435.
11. Wagstaff AJ, Benfield P & Monk JP: Colloidal bismuth subcitrate: a review of its pharmacodynamic and pharmacokinetic properties, and its therapeutic use in peptic ulcer disease. Drugs 1988; 36:132-157.
12. Product Information: Vantin(R), cefpodoxime. Pharmacia & Upjohn Company, Kalamazoo, MI, (PI revised 11/2000) reviewed 3/2002.
13. Shiba K, Sakai O, Shimada J et al: Effects of antacids, ferrous sulfate, and ranitidine on absorption of DR-3355 in humans. Antimicrob Agents Chemother 1992; 36:2270-2274.
14. D'Arcy PF & McElnay JC: Drug-antacid interactions: assessment of clinical importance. Drug Intell Clin Pharm 1987; 21:607-617.
15. Carlson JA, Mann HJ & Canafax DM: Effect of pH on disintegration and dissolution of ketoconazole tablets. Am J Hosp Pharm 1983; 40:1334-1336.
16. Product Information: Sporanox(R), itraconazole. Janssen Pharmaceutica Products, L.P., Titusville, New Jersey, (PI revised 2/2002) reviewed 5/2002.
17. Product Information: Levsin(R), hyoscyamine sulfate. Schwarz Pharma, Inc., Milwaukee, WI, 1996.
18. Product Information: Pamine(R), methscopolamine. Upjohn Company, Kalamazoo, MI, 1991.
19. Baluarte HJ, Prebis J, Goldberg M et al: Metabolic alkalosis in an anephric child caused by the combined use of Kayexalate(R) and Basaljel(R). J Pediatr 1978; 92:237.
20. Product Information: Tritec(R), ranitidine bismuth citrate. Glaxo Wellcome Inc., Research Triangle Park, NC, 1999.
21. Product Information: Carafate(R), sucralfate. Hoechst Marion Roussel, Inc., Kansas City, MO, 1996.
22. Shah J, Fratis A, Ellis D et al: Effect of food and antacid on absorption of orally administered ticlopidine hydrochloride. J Clin Pharmacol 1990; 30:733-736.
23. O'Neil-Cutting MA & Crosby WH: The effect of antacids on the absorption of simultaneously ingested iron. JAMA 1986; 255:1468-1470.
24. Heaney RP, Smith KT, Recker RR et al: Meal effects on calcium absorption. Am J Clin Nutr 1989; 49(2):372-376.
25. Kirch W, Schafer-Korting M, Axthelm T, et al: Interaction of atenolol with furosemide and calcium and aluminum salts. Clin Pharmacol Ther 1981; 30:429-435.
26. Mantyla R, Mannisto PT, Vuorela A, et al: Impairment of captopril bioavailability by concomitant food and antacid intake. Int J Clin Pharmacol Ther Toxicol 1984a; 22:626-629.
27. Carlson JA, Mann HJ, & Canafax DM: Effect of pH on disintegration and dissolution of ketoconazole tablets. Am J Hosp Pharm 1983; 40:1334-1336.
28. Van der Meer JWM, Keuning JJ, Scheijgrond HW, et al: The influence of gastric acidity on the bioavailability of ketoconazole. J Antimicrob Chemother 1980; 6:552-554.
29. Marchbanks CR: Drug-drug interactions with fluoroquinolones. Pharmacotherapy 1993; 13:23S-28S.
30. Product Information: Actonel(TM), risedronate. Procter & Gamble Pharmaceuticals, Inc., Cincinnati, OH, 1998.
31. Product Information: Agenerase®, amprenavir. Glaxo Wellcome Inc., Research Triangle Park, NC, 2000.
32. Product Information: Lexiva(TM), fosamprenavir. GlaxoSmithKline, Research Triangle Park, NC, 2003.
33. Baldwin JR, Borin MT, Wang Y, et alBaldwin JR, Borin MT, Wang Y, et al: Effects of food and antacid on bioavailability of the protease inhibitor PNU-140690 in healthy volunteers (abstract), 5th Conf Retrovir Oppor Inf, Chicago, 1998.
34. Product Information: Spectracef(TM), cefditoren pivoxil. TAP Pharmaceuticals, Inc., Lake Forest, Illinois, 2001.
35. Product Information: Boniva(TM), ibandronate sodium tablets. GlaxoSmithKline, Research Triangle Park, NC, 2003.
36. Product Information: Levsin(R), hyoscyamine sulfate. Schwarz Pharma, Inc., Milwaukee, WI, 1996.
37. Delhotal-Landes B, Cournot A, Vermerie N, et al: The effect of food and antacids on lansoprazole absorption and disposition. Eur J Drug Metab Pharmacokinet 1991; Spec No 3:315-320.
38. Dobbs JH, Skoutakis VA, Acchiardo SR, et al: Effects of aluminum hydroxide on the absorption of propranolol. Curr Ther Res 1977; 21:887-892.
39. Ziessman HA: Alkalosis and seizure due to a cation exchange resin and magnesium hydroxide. South Med J 1976; 69:497-499.
40. Fernandez PC & Kovnat PJ: Metabolic acidosis reversed by the combination of magnesium hydroxide and cation exchange resin. N Engl J Med 1972; 286:23.
41. Schroeder ET: Alkalosis resulting from combined administration of a "non-systemic" antacid and a cation-exchange resin. Gastroenterology 1969; 56:868.
42. Product Information: Carafate(R), sucralfate. Hoechst Marion Roussel, Inc., Kansas City, MO, 1996.
43. Shah J, Fratis A, Ellis D, et al: Effect of food and antacid on absorption of orally administered ticlopidine hydrochloride. J Clin Pharmacol 1990; 30:733-736.
44. Product Information: Skelid(R), tiludronate. Sanofi Pharmaceuticals, Inc., New York, NY, 1998.
45. Feldman S & Carlstedt BC: Effects of antacid on absorption of enteric-coated aspirin. JAMA 1974; 227:660.
46. Strickland-Hodge B, Thomas TR, Gould WA, et al: The effects of antacids on enteric-coated salicylate preparations. Rheumatol Rehabil 1976; 15:148-152.
47. Shastri RA: Effect of antacids on salicylate kinetics. Int J Clin Pharmacol Ther Toxicol 1985; 23:480-484.
48. Gaspari F, Vigano G, Tocatelli M, et al: Influence of antacid administrations on aspirin absorption in patients with chronic renal failure on maintenance hemodialysis. Am J Kidney Dis 1988; 11:338-342.
49. Product Information: Dulcolax(R), bisacodyl. Boehringer Ingelheim Pharmaceuticals, Ridgefield, CT, 1993.
50. O'Neil-Cutting MA & Crosby WH: The effect of antacids on the absorption of simultaneously ingested iron. JAMA 1986; 255:1468-1470.
51. Wood RJ & Zheng JJ: High dietary calcium intakes reduce zinc absorption and balance in humans. Am J Clin Nutr 1997; 65(6):1803-1809.
52. Gulliford MC, Pover GG, Bicknell EJ, et al: Guar delays intestinal calcium absorption in man. Eur J Clin Nutr 1988; 42(5):451-454.
53. Product Information: Os-Cal(R), calcium carbonate. GlaxoSmithKline, 2004.
54. Product Information: Rocephin(R) injection, ceftriaxone sodium injection. Roche Pharmaceuticals, Nutley, NJ, 2008.
55. Product Information: TARCEVA(R) oral tablets, erlotinib oral tablets. OSI Pharmaceuticals Inc, Melville, NY, 2008.
56. Product Information: PROMACTA(R) oral tablets, eltrombopag oral tablets. Glaxo Smith Kline, Research Triangle Park, NC, 2008.
Last Updated: 1/4/2018