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Is Vitamin D (cholecalciferol / D3 supplements) toxic to dogs or cats?
Category: Medication | Last reviewed: June 2026
Quick verdict
Dogs
TOXICCats
TOXICVitamin D (cholecalciferol / D3 supplements) and dogs
Vitamin D has a narrow margin of safety. Excess cholecalciferol (D3) drives blood calcium and phosphorus dangerously high, causing soft-tissue mineralisation and acute kidney failure within 2-3 days. Sources include high-dose human D3 supplements, some psoriasis creams (calcipotriene), and cholecalciferol rodenticides. Even with aggressive treatment, kidney damage can be permanent.
Onset
12-72 hours; hypercalcaemia 18-72 hours, kidney injury 2-3 days
Symptoms
- - increased thirst and urination
- - vomiting
- - loss of appetite
- - weakness
- - lethargy
- - ammonia-smelling breath
- - kidney failure
What to do now
Contact ASPCA Poison Control (888-426-4435) or your vet. Bloodwork to monitor calcium over several days is usually needed. Bring the product so the strength can be assessed.
Toxicity is dose-dependent. Your dog's weight and the quantity consumed are both important - include these when you call poison control.
Vitamin D (cholecalciferol / D3 supplements) and cats
Cats are even more sensitive to cholecalciferol than dogs, and excess vitamin D in pet food has caused poisoning in cats. The same hypercalcaemia and kidney-failure mechanism applies.
Onset
12-72 hours; kidney injury 2-3 days
Symptoms
- - increased thirst and urination
- - vomiting
- - loss of appetite
- - weakness
- - lethargy
- - kidney failure
What to do now
Contact ASPCA Poison Control (888-426-4435) or your vet. Calcium monitoring over several days is usually required.
Data sources
- - ASPCA Animal Poison Control
- - Pet Poison Helpline - Cholecalciferol
- - Merck Veterinary Manual
- - VCA Animal Hospital
Last reviewed: June 2026
Data error? Email data@treatortoxic.com with a source reference.