Vetdrugs 2.0Calcium citrate is an oral calcium salt used for nutritional supplementation and longer-term correction of calcium deficiency. It provides approximately 21% elemental calcium by weight and can be absorbed without the same dependence on gastric acidity as calcium carbonate. In small animals, its principal roles are calcium replacement and, in selected patients, intestinal phosphate binding.
Group
Calcium supplement
Mechanism of Action
After dissolution in the gastrointestinal tract, calcium citrate supplies calcium ions that enter the circulating calcium pool. Ionized calcium supports neuromuscular excitability, muscle contraction, intracellular signaling and skeletal mineralization. Replacing a deficient calcium supply helps restore these functions. Calcium remaining in the intestinal lumen can combine with dietary phosphate to form poorly absorbed complexes, reducing phosphate uptake.
Dose Rates
Cats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Calcium supplementation | Reference only | PO | 10–30 mg/kg orally every 8 hours with meals; salt-versus-elemental basis is not explicitly assigned. | |
| Phosphate binding | Reference only | PO | 10–20 mg/kg total daily, divided with meals orally; elemental-versus-salt basis is not explicit. |
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Calcium supplementation | Reference only | PO | 20 mg/kg total daily orally with meals; salt-versus-elemental basis is not explicitly assigned. | |
| Phosphate binding | Reference only | PO | 10–20 mg/kg total daily, divided with meals orally; elemental-versus-salt basis is not explicit. |
Indications
- Oral supplementation for dietary calcium deficiency or inadequate calcium intake in dogs and cats.
- Maintenance treatment of hypocalcemia associated with hypoparathyroidism in dogs and cats, commonly as part of a calcium and active-vitamin-D regimen.
- Intestinal phosphate binding in selected dogs and cats with chronic kidney disease and hyperphosphatemia.
Contraindications
- Hypercalcemia.
- Use cautiously with calcium-containing urinary calculi or kidney disease.
- Hypercalcemia; use particular caution with cardiac disease, renal disease or concurrent digitalis glycosides.
Interactions
- Oral calcium can impair absorption of iron, tetracyclines and fluoroquinolones.
- Avoid mixing injectable calcium with bicarbonate, phosphate, sulfate or tartrate solutions.
- Digitalis glycosides increase sensitivity to calcium-associated arrhythmias.
Adverse effects
- Hypercalcemia
- Constipation with oral supplementation
- Arrhythmias with rapid intravenous calcium
Toxicity
Excess calcium can cause hypercalcemia, cardiac instability and tissue mineralization.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Calcium Citrate 950 mg tablet | Tablet | 950 mg / tablet | PO |
| Calcium Citrate 1000 mg tablet | Tablet | 1000 mg / tablet | PO |
Monitoring and Administration
Monitor ionized calcium and clinical response; phosphate monitoring is needed when used as a binder. Monitor heart rate and ECG during intravenous treatment.
Give intravenous calcium slowly. Avoid extravasation; injectable calcium can cause severe tissue injury. Route suitability is product-specific.
Calcium citrate contains about 21% elemental calcium; 950 mg salt supplies approximately 200 mg elemental calcium. It does not require gastric acid for absorption. The dose passage does not state whether its mg/kg amounts are salt mass or elemental calcium.
When indicated, monitor magnesium, phosphorus, potassium, renal function and urinary calcium as well as serum calcium. Do not infer compatibility of an admixture from compatibility with a different diluent or concentration.
A general canine hypoparathyroidism maintenance guideline uses approximately 25 mg/kg ELEMENTAL calcium orally every 8–12 hours, with vitamin D and calcium monitoring. This does not retrospectively establish the salt basis of the older citrate-specific dose bullets.