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Calcium phosphate, tribasic

Generic name: calcium phosphate, tribasic (tricalcium phosphate) [ KAL-see-um-FOSS-fate, tri-BAY-sick ]
Brand name: Posture
Dosage form: oral tablet (600 mg)
Drug class: Minerals and electrolytes

Medically reviewed by on Jun 26, 2023. Written by Cerner Multum.

What is calcium phosphate?

Calcium phosphate (tricalcium phosphate) is a mineral that is used as a supplement in people who do not get enough calcium from food.

Calcium phosphate is used to treat calcium deficiencies that may be associated with low blood calcium, a parathyroid disorder, or osteoporosis and other bone conditions.

Calcium phosphate may also be used for purposes not listed in this medication guide.

Calcium phosphate side effects

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

Calcium phosphate may cause serious side effects. Stop using calcium phosphate and call your doctor at once if you have:

Less serious side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Follow all directions on the label and package. Use exactly as directed.

Before taking this medicine

Ask a doctor or pharmacist if calcium phosphate, tribasic is safe to use if you have ever had:

Ask a doctor before using this medicine if you are pregnant or breastfeeding.

Do not give this medicine to a child without medical advice.

How should I take calcium phosphate?

Use exactly as directed on the label, or as prescribed by your doctor.

Take with food.

If you take more than 1 tablet, space your doses evenly at different times of the day.

You may need medical tests.

You may need to follow a special diet or take vitamin D supplements. Follow all instructions of your doctor or dietitian. Learn about the foods you should eat or avoid.

Store at room temperature away from moisture and heat.

Calcium phosphate, tribasic dosing information

Usual Adult Dose for Hypocalcemia:

1 to 2 tablets orally once a day.

Usual Adult Dose for Osteomalacia:

1 to 2 tablets orally once a day.

Usual Adult Dose for Osteoporosis:

1 to 2 tablets orally once a day.

Usual Adult Dose for Pseudohypoparathyroidism:

1 to 2 tablets orally once a day.

Usual Adult Dose for Hypoparathyroidism:

1 to 2 tablets orally once a day.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

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

Overdose may cause nausea, vomiting, loss of appetite, weakness, or tiredness, headache, or mood changes.

What should I avoid while taking calcium phosphate?

Ask your doctor before using an antacid, and use only the type your doctor recommends.

What other drugs will affect calcium phosphate?

Ask a doctor or pharmacist before using calcium phosphate with any other medications, especially

This list is not complete. Other drugs may affect calcium phosphate, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.