Calcium supplements - oral
Oyster Shell Calcium 500 mg calcium (1,250 mg) tablet
This medication is used to prevent or treat low blood calcium levels in people who do not get enough calcium from their diets. It may be used to treat conditions caused by low calcium levels such as bone loss (osteoporosis), weak bones (osteomalacia/rickets), decreased activity of the parathyroid gland (hypoparathyroidism), and a certain muscle disease (latent tetany). It may also be used in certain patients to make sure they are getting enough calcium (such as women who are pregnant, nursing, or postmenopausal, people taking certain medications such as phenytoin, phenobarbital, or prednisone).
Calcium plays a very important role in the body. It is necessary for normal functioning of nerves, cells, muscle, and bone. If there is not enough calcium in the blood, then the body will take calcium from bones, thereby weakening bones. Having the right amount of calcium is important for building and keeping strong bones.
Take this medication by mouth with food. If your product contains calcium citrate, then it may be taken with or without food. Follow all directions on the product package, or take as directed by your doctor. For best absorption, if your daily dose is more than 600 milligrams, then divide your dose and space it throughout the day. If you have any questions, ask your doctor or pharmacist.
If you are using the chewable product, chew it well before swallowing.
If you are using the effervescent tablet, allow the tablet to fully dissolve in a glass of water before drinking it. Do not chew or swallow the tablet whole.
If you are using the liquid product or powder, measure the medication with a dose-measuring spoon or device to make sure you get the correct dose. Do not use a household spoon. If the liquid product is a suspension, shake the bottle well before each dose.
Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time(s) each day.
If your doctor has recommended that you follow a special diet, it is very important to follow the diet to get the most benefit from this medication and to prevent serious side effects. Do not take other supplements/vitamins unless ordered by your doctor.
If you think you may have a serious medical problem, get medical help right away.
Constipation and upset stomach may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
If your doctor has directed you to use this medication, remember that your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away if you have any serious side effects, including:
- loss of appetite
- unusual weight loss
- mental/mood changes
- bone/muscle pain
- increased thirst/urination
- unusual tiredness
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:
- itching/swelling (especially of the face/tongue/throat)
- severe dizziness
- trouble breathing
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Before taking calcium, tell your doctor or pharmacist if you have any allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
If you have any of the following health problems, consult your doctor or pharmacist before using this product:
- high calcium levels (hypercalcemia)
- kidney disease (including kidney stones)
- little or no stomach acid (achlorhydria)
- heart disease
- disease of the pancreas
- a certain lung disease (sarcoidosis)
- difficulty absorbing nutrition from food (malabsorption syndrome)
Some sugar-free formulations of calcium may contain aspartame. If you have phenylketonuria (PKU) or any other condition that requires you to restrict your intake of aspartame (or phenylalanine), consult your doctor or pharmacist about using this drug safely.
Tell your doctor if you are pregnant before using this medication.
This medication passes into breast milk. Consult your doctor before breast-feeding.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
Some products that may interact with this drug are:
- cellulose sodium phosphate
- certain phosphate binders (such as calcium acetate)
Calcium can decrease the absorption of other drugs such as bisphosphonates (for example, alendronate), tetracycline antibiotics (such as doxycycline, minocycline), estramustine, levothyroxine, and quinolone antibiotics (such as ciprofloxacin, levofloxacin). Separate your doses of these medications as far as possible from your doses of calcium. Ask your doctor or pharmacist about how long you should wait between doses and for help finding a dosing schedule that will work with all your medications.
Check the labels on all your prescription and nonprescription/herbal products (such as antacids, vitamins) because they may contain calcium. Ask your pharmacist about using those products safely.
If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: nausea/vomiting, loss of appetite, mental/mood changes, headache, weakness, tiredness.
Foods rich in calcium include: dairy products (such as milk, yogurt, cheese, ice cream), dark-green leafy vegetables (such as broccoli, spinach, bok choy), and calcium-fortified foods (such as orange juice).
Vitamin D helps with the absorption of calcium. Foods rich in vitamin D include: fortified dairy products, eggs, sardines, cod liver oil, chicken livers, and fatty fish. Vitamin D is also made by the body as a result of exposure to the sun.
Lab and/or medical tests (such as calcium levels) may be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.
If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Information last revised March 2023.
Copyright(c) 2023 First Databank, Inc.
Selected from NATIONAL DRUG DATA FILE (NDDF) data included with permission and copyrighted by First Databank, Inc., 2019. This copyrighted material has been downloaded from a licensed data provider.
The above information is intended to supplement, not substitute for, the expertise and judgment of your health care professional. You should consult your health care professional before taking any drug, changing your diet, or commencing or discontinuing any course of treatment.