What are the symptoms of Vitamin D3 (cholecalciferol) poisoning in cats?

vomiting, increased thirst, lethargy, decreased urination

Vitamin D3 (cholecalciferol)

Q: What if my cat ate Vitamin D3 (cholecalciferol)?

Dangerous: Dangerous — extra vitamin D raises calcium until the kidneys fail. Cholecalciferol is in some rodenticides and in high-dose human vitamin D. Cats that eat either can develop severe hypercalcemia — increased thirst, vomiting, then kidney injury. The dangerous dose is much smaller than people expect from a “vitamin.” Source: ASPCA.

Q: Is Iron supplements also safe for cats?

Toxic: Toxic — elemental iron in adult or prenatal tablets can damage the gut and liver.

Dangerous

Verdict

Dangerous — extra vitamin D raises calcium until the kidneys fail.

Toxic principle: cholecalciferol (severe hypercalcemia)

Also called: cholecalciferol, vitamin d cream, vitamin d, d3

Source: ASPCA · Verified 2026-08-13

If your cat ate this

Cats hide symptoms — don't wait and see. Even small amounts of certain substances can be fatal to a cat. Act fast.

1. Call your veterinarian immediately
US — National hotline: ASPCA Animal Poison Control Center (888) 426-4435 aspca.org(24/7, Consultation fee may apply.)
US — National hotline: Pet Poison Helpline (855) 764-7661 petpoisonhelpline.com(24/7, $89 per incident fee; also covers Canada.)
GB — National hotline: Animal PoisonLine 01202 509 000 animalpoisonline.co.uk(24/7, £35 per call (8am–8pm weekdays), £45 at other times.)
AU — National hotline: Animal Poisons Helpline 1300 869 738 animalpoisons.com.au(24/7)
NZ — National hotline: Animal Poisons Helpline 0800 869 738 poisons.co.nz(11am–7pm NZ time (currently being extended), Charges apply.)
CA — National hotline: Pet Poison Helpline (855) 764-7661 petpoisonhelpline.com(24/7, $89 per incident fee.)

Verified 2026-08-06

Verdict

Cholecalciferol is in some rodenticides and in high-dose human vitamin D. Cats that eat either can develop severe hypercalcemia — increased thirst, vomiting, then kidney injury. The dangerous dose is much smaller than people expect from a “vitamin.”

Symptoms to watch for

• vomiting
• increased thirst
• lethargy
• decreased urination

What to do

Bring the bottle or bait box. This needs bloodwork. Call a vet now.

ASPCA Animal Poison Control Center: (888) 426-4435 aspca.org

Related foods

Iron supplements

Toxic

Toxic — elemental iron in adult or prenatal tablets can damage the gut and liver.

Over the counter

Diphenhydramine (Benadryl)

Caution

Do not self-medicate. If a cat ate a human tablet, call a vet — this site will not give a dose.

Over the counter

Melatonin

Caution

Do not self-medicate. If ingested, call a vet — check the label for xylitol.

Over the counter

Acetaminophen (Tylenol)

Dangerous

Never — a single regular-strength tablet can kill a cat.

Pain relievers