Medication safety · 2 min read

Is Vitamin D supplements (cholecalciferol) toxic to cats?

No — dangerous

No. Vitamin D supplements — especially high-strength D3 — are toxic to cats. Cholecalciferol is also the active ingredient in some rodent baits.

If your cat has just eaten vitamin d supplements (cholecalciferol)

  1. Note the strength (IU per tablet) and number eaten.
  2. Call your vet immediately.
  3. If you can't reach a vet, call Animal PoisonLine (01202 509000) — paid triage, 24/7.

What's the full picture?

High doses of vitamin D3 (cholecalciferol) cause calcium to rise dangerously in the blood, which damages the kidneys, heart, and GI tract.

Toxicity isn't just from human supplements — some rodent poisons use cholecalciferol (e.g. certain rat-bait products), and a cat that eats a poisoned rodent or the bait itself can be affected.

Symptoms to watch for

0–24 hours
Vomiting, loss of appetite, excessive thirst and urination, weakness.
24–72 hours
Kidney injury signs, constipation, depression.
72+ hours
Acute kidney failure in severe exposures.

If you're worried right now

Call your vet or out-of-hours emergency vet first. For poison advice, the Animal PoisonLine (UK) is on 01202 509000 — 24/7, charges apply. Your vet can also call the Veterinary Poisons Information Service (VPIS) directly.

Fish oil / omega-3 supplements caution Iron supplements no Paracetamol no Rat poison no Topical creams (5-FU, calcipotriene, hormone creams) no

About this guidance

Every entry on this site is compiled from published UK veterinary toxicology sources — International Cat Care, Veterinary Poisons Information Service (VPIS) references, RCVS-registered practice materials, and peer-reviewed feline medicine literature. Where the evidence is mixed, we err on the cautious side because cats are unusually sensitive to many common substances that are harmless to humans and even to dogs.

This is general information written for UK cat owners. It is not personalised veterinary advice for your specific cat, their age, weight, medical history, or the exact exposure you're dealing with. If your cat has eaten something or is unwell, call your vet first. The Animal PoisonLine on 01202 509000 is available 24/7 for a small fee and can tell you whether an emergency visit is needed.

Entries are reviewed and updated as new research emerges. Spotted an error? Let us know — corrections are investigated and applied within 24 hours. For more context on how we work, see about and our full disclaimer.

Last reviewed: · By the What Can My Cat Eat? editorial team

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