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Calcium Oyster Shell

Generic name: calcium carbonate

Brand names: Alka-Mints, Alka-Seltzer Cool Action Heartburn Relief, Alka-Seltzer Extra Strength Heartburn Relief, Calcium Oyster Shell, Cal-Gest, Icar Prenatal Chewable Calcium, Oyster Cal, Oyster Calcium, Oyster Shell, Oyster Shell Calcium, Oyster Shell Calcium 500, Tums, Tums Antacid Naturals, Tums Chewy Bites, Tums Chewy Bites Ultra Strength, Tums Chewy Delights, Tums E-X, Tums Smoothies, Tums Smoothies Extra Strength, Tums Sugar-Free

Last updated November 1, 2026 0 views
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What is Calcium Oyster Shell?

Calcium is a mineral that occurs naturally in foods. It is essential for many normal body functions, particularly for building and maintaining bones.

Calcium Oyster Shell is used to prevent or treat a calcium deficiency.

There are many brands and forms of calcium carbonate available. Not all brands are mentioned in this leaflet.

Calcium Oyster Shell may also be used for reasons not included in this medication guide.

This section was rewritten for readability and reviewed for meaning.

How should I take Calcium Oyster Shell?

Use exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Check the label of your Calcium Oyster Shell product to see if it should be taken with or without food.

Swallow the Calcium Oyster Shell regular tablet with a full glass of water.

The chewable tablet should be chewed before you swallow it.

Shake the oral suspension (liquid) well just before you measure a dose. Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.

Use the Calcium Oyster Shell powder as directed. Allow the powder to dissolve completely, then consume the mixture.

Calcium Oyster Shell may be only part of a complete program of treatment that also includes dietary changes. Learn about the foods that contain calcium.

Your Calcium Oyster Shell dose may need to be adjusted as you make changes to your diet. Follow your doctor's instructions very closely.

Store at room temperature away from moisture and heat. Do not freeze.

This section was rewritten for readability and reviewed for meaning.

Warnings

Follow all instructions on your medicine label and package. Inform all your healthcare providers about your medical conditions, allergies, and all medicines you are taking.

This section was rewritten for readability and reviewed for meaning.

Before taking this medicine

Ask a doctor or pharmacist if it is safe for you to take Calcium Oyster Shell if you have ever had:

  • kidney disease;
  • kidney stones;
  • cancer;
  • a parathyroid gland disorder; or
  • high levels of calcium in your blood.

Ask a doctor before using Calcium Oyster Shell if you are pregnant or breastfeeding. Your dose may need to be different during pregnancy or while you are nursing.

This section was rewritten for readability and reviewed for meaning.

Calcium Oyster Shell side effects

Get emergency medical help if you notice any signs of an allergic reaction: hives; trouble breathing; swelling of your face, lips, tongue, or throat.

Calcium Oyster Shell can cause serious side effects. Contact your doctor immediately if you experience:

  • little or no urination;
  • swelling, rapid weight gain; or
  • high calcium levels in your blood—nausea, vomiting, constipation, increased thirst or urination, muscle weakness, bone pain, confusion, lack of energy, or feeling tired.

Common side effects of Calcium Oyster Shell may include:

  • upset stomach, gas; or
  • constipation.

This is not a complete list of side effects, and others may happen. Reach out to your doctor for medical advice about side effects. You can report side effects to the FDA at 1-800-FDA-1088.

This section was rewritten for readability and reviewed for meaning.

What happens if I miss a dose?

Take the missed dose as soon as you remember. If it is almost time for your next scheduled dose, skip the missed dose. Do not take extra medicine to make up for the missed dose.

This section was rewritten for readability and reviewed for meaning.

What happens if I overdose?

Seek emergency medical help or call the Poison Help line at 1-800-222-1222.

Talk to a doctor or pharmacist before using any multivitamins, mineral supplements, or antacids while you are taking Calcium Oyster Shell.

This section was rewritten for readability and reviewed for meaning.

What other drugs can affect Calcium Oyster Shell?

Calcium can make it harder for your body to absorb some medicines. If you take other medications, take them at least 2 hours before or 4 to 6 hours after you take Calcium Oyster Shell.

Other drugs may interact with calcium carbonate, including prescription and over-the-counter medicines, vitamins, and herbal products. Inform your doctor about all your current medicines and any medicine you start or stop using.

This section was rewritten for readability and reviewed for meaning.

Related medicines

Before you take this medicine: the information on this page is general and may not cover your personal circumstances. Read the label supplied with your medicine and ask a pharmacist or doctor if you are unsure, especially if you are pregnant, breastfeeding, taking other medicines or managing a long-term condition.
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Content is provided for education and is not medical advice. See our medical disclaimer.