Calcium Supplements


Pictured: Supplement

Poisonous to: Cats, Dogs

Level of toxicity: Generally mild to moderate

Common signs to watch for:

  • Nausea
  • Vomiting
  • Diarrhea
  • Constipation
  • Excessive thirst or urination
  • Weakness
  • Acute kidney failure

Calcium supplements usually come in tablet or flavored soft-chew formulations and are readily found in many households. When dogs ingest these supplements in large amounts, vomiting and diarrhea or constipation are common, with potential for transiently elevated calcium blood levels. Cats generally do not ingest enough of these supplements to result in poisoning due to their discriminating palate. Calcium supplements may also contain Vitamin D3 which can also contribute to toxicity. While calcium alone is generally poorly absorbed from the gastrointestinal tract, Vitamin D3 significantly increases its absorption and the risk of toxicity.

Ingestion of supplements containing calcium alone are safer than ingestion of supplements containing types of Vitamin D (e.g., cholecalciferol, calcipotriene), which can be deadly. Signs of poisoning include nausea, vomiting, and diarrhea or constipation. If the supplement also contains Vitamin D, there is potential for excessive thirst or urination, weakness, increased blood calcium, and acute kidney failure to develop depending on the dose ingested.

Poison type: medications

Alternate names: vitamin D3, cholecalciferol, Viactiv, Tums, Caltrate, Os-Cal, hypercalcemia