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Posture Side Effects

Generic name: calcium phosphate, tribasic

Note: This document contains side effect information about calcium phosphate, tribasic. Some dosage forms listed on this page may not apply to the brand name Posture.

Applies to calcium phosphate, tribasic: oral tablet.


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

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

Stop using calcium phosphate and call your doctor at once if you have:

Less serious side effects of calcium phosphate, tribasic (the active ingredient contained in Posture) may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

For Healthcare Professionals

Applies to calcium phosphate, tribasic: oral tablet, oral tablet chewable.


Gastrointestinal side effects have included nausea in up to 9% of patients receiving calcium phosphate with vitamin D and fluoride.[Ref]


Metabolic side effects have included hyperphosphatemia and hypercalciuria. Hypercalcemia has been reported with some calcium salts; however, it has not yet been associated with the use of calcium phosphate.[Ref]

Metabolic changes associated with some calcium salts include hypercalcemia, although this has not yet been associated with the use of calcium phosphate.

Hyperphosphatemia can result from overuse.

Prolonged calcium administration of some calcium salts has rarely resulted in hypercalciuria. This may be more likely in patients with hypoparathyroidism who are receiving vitamin D.[Ref]


Cardiovascular side effects have included a single case report of systemic tricalcium phosphate crystallosis involving the heart (myocarditis and pericarditis).[Ref]


1. Cleghorn GJ, Tudehope DI (1981) "Neonatal intestinal obstruction associated with oral calcium supplementation." Aust Paediatr J, 17, p. 298-9

2. Hasling C, Nielsen HE, Melsen F, Mosekilde L (1987) "Safety of osteoporosis treatment with sodium fluoride, calcium phosphate and vitamin D." Miner Electrolyte Metab, 13, p. 96-103

3. Edelson GW, Kleerekoper M (1995) "Hypercalcemic crisis." Med Clin North Am, 79, p. 79-92

4. Breuer RI, LeBauer J (1967) "Caution in the use of phosphates in the treatment of severe hypercalcemia." J Clin Endocrinol Metab, 27, p. 695-8

5. Chaudhuri TK, Chaudhuri TuH (1972) "Calcium phosphate colloid: possible nidus for metastatic calcification in hypercalcemia." JAMA, 222, p. 1061

6. Knowles JB, Cusson G, Smith M, Sitrin MD (1989) "Pulmonary deposition of calcium phosphate crystals as a complication of home total parenteral nutrition." JPEN J Parenter Enteral Nutr, 13, p. 209-13

7. Reimann HA, Imbriglia JE, Ducanes T (1966) "Crystal-induced myocarditis and pericarditis." Am J Cardiol, 17, p. 269-72

Further information

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

Some side effects may not be reported. You may report them to the FDA.