DogPoisonCheck

    Dog Ate Vitamin D: Toxicity, Symptoms & What to Do

    URGENT — Contact your veterinarian or a poison control hotline now

    Quick answer

    Merck reports cholecalciferol (vitamin D3) signs in dogs from doses as low as 0.1 mg/kg (4,000 IU/kg; 1 mcg = 40 IU) and soft-tissue mineralization above 0.5 mg/kg, and ASPCA APCC reports signs at 0.5 mg/kg; call your veterinarian after any ingestion of supplements or vitamin D rodent bait.

    Published reference: Merck Veterinary Manual — cholecalciferol poisoning; ASPCA APCC Toxicology Brief — cholecalciferol poisoning

    Use the vitamin D toxicity calculator

    Find an Emergency VetCheck your dog's risk

    Did your dog eat something else too?

    Chocolate Grapes / Raisins Onions Xylitol Ibuprofen Rat poison

    Sources reviewed 14 Oct 2026·Last updated · 2 min read

    Is vitamin d toxic to dogs?Toxic dose by dog weightSymptoms timelineGo to the vet / call ASPCA Animal Poison Control (888) 426-4435 now if…First aid: do's and don'tsHow vets treat vitamin d exposurePrognosis

    Vitamin D is on our critical-substance reference list.

    If your dog has ingested any amount, contact your veterinarian. 24/7 animal poison-control hotlines (ASPCA Animal Poison Control Center, Pet Poison Helpline) are also available — fees may apply.

    Dose figures describe published observations, not a safe home-treatment threshold. Use the cited reference and contact a veterinarian for your dog's exposure.

    Want this scaled to your dog?

    Personalized to your dog's exact weight, age, and timing. Takes 90 seconds.

    Get my dog's report

    Symptoms timeline

    1. 0-2 Hours
      • Often no signs yet
      • Vomiting
    2. 2-12 Hours
      • Loss of appetite
      • Increased thirst and urination
      • Weakness
    3. 12-72 Hours
      • Kidney failure
      • Abnormal heart rhythm
      • Tissue mineralization
    4. Days later
      • Calcium and kidney changes can keep developing for days; vets look for normal calcium and phosphorus 72–96 hours after eating (Merck Veterinary Manual). If in doubt, call your vet.

    Is vitamin d toxic to dogs?

    High-dose vitamin D supplements, some rat poisons and psoriasis creams can raise a dog's calcium to dangerous levels, leading to kidney failure. Signs are often delayed by a day or more. The toxic principle is cholecalciferol and analogues raising blood calcium and phosphorus.

    Toxic dose by dog weight

    Merck Veterinary Manual reports clinical signs from cholecalciferol (vitamin D3) doses as low as 0.1 mg/kg and calcium/phosphorus rises leading to soft-tissue mineralization above 0.5 mg/kg; ASPCA APCC reports signs at 0.5 mg/kg. 1 mcg = 40 IU, so 0.1 mg/kg is 4,000 IU per kg. These are reported levels, not safe allowances. Calcitriol and calcipotriene are far more potent and not interchangeable with cholecalciferol. Bring the exact product and concentration to the veterinarian.

    Published dose reference: Merck Veterinary Manual — cholecalciferol poisoning; ASPCA APCC Toxicology Brief — cholecalciferol poisoning.

    Symptoms timeline

    0–2 hours: often no signs yet, vomiting.

    2–12 hours: loss of appetite, increased thirst and urination, weakness.

    12–72 hours: kidney failure, abnormal heart rhythm, tissue mineralization.

    Days later: calcium and kidney changes can keep developing for days; vets look for normal calcium and phosphorus 72–96 hours after eating (Merck Veterinary Manual). If in doubt, call your vet.

    Go to the vet / call ASPCA Animal Poison Control (888) 426-4435 now if…

    • Your dog ate high-dose vitamin D supplements, a rodenticide containing cholecalciferol, or psoriasis cream
    • Your dog is drinking and urinating much more than normal
    • You are unsure what or how much your dog ate
    • Your dog is very young, old, pregnant or has heart, liver or kidney disease

    First aid: do's and don'ts

    Do:

    • Move your dog away from the source and remove any remaining material from their mouth if it is safe to do so
    • Keep the packaging, label or a sample/photo of what was eaten
    • Note your dog's weight, the approximate amount and the time of ingestion
    • Call your vet or a pet poison hotline right away

    Don't:

    • Never induce vomiting without veterinary advice — for some substances it causes more harm
    • Don't give salt, hydrogen peroxide, oils or home remedies unless a vet tells you to
    • Don't wait for symptoms if the substance is highly toxic
    • Don't give human medicines to treat symptoms

    How vets treat vitamin d exposure

    Treatment depends on the amount, time since ingestion and your dog's signs. It may include decontamination when appropriate, activated charcoal for some toxins, IV fluids, medications to control signs, and monitoring. Bring the packaging so your vet can tailor treatment.

    Prognosis

    Most dogs treated early do well. The outlook depends on the dose, how quickly care begins, and your dog's overall health. Severe or delayed cases carry a more guarded prognosis.

    What to do now

    Call your veterinarian or an animal poison-control service for exposure-specific advice. Dog poison control: phone numbers, fees and when to call.

    Personalized report

    Get a personalized vitamin d report for your dog

    Scaled to your dog's exact weight, age, and timing · Published toxicology sources · Instant download

    • Scaled to your dog's exact weight
    • Specific to time-since-ingestion
    • Vet talking points ready to read on the phone
    Get my dog's personalized report

    Takes 90 seconds · Personalized to your dog.

    Frequently asked questions about vitamin d and dogs

    How much vitamin d is toxic to dogs?▾

    Merck Veterinary Manual reports clinical signs from cholecalciferol (vitamin D3) doses as low as 0.1 mg/kg and calcium/phosphorus rises leading to soft-tissue mineralization above 0.5 mg/kg; ASPCA APCC reports signs at 0.5 mg/kg. 1 mcg = 40 IU, so 0.1 mg/kg is 4,000 IU per kg. These are reported levels, not safe allowances. Calcitriol and calcipotriene are far more potent and not interchangeable with cholecalciferol. Bring the exact product and concentration to the veterinarian.

    Published dose reference: Merck Veterinary Manual — cholecalciferol poisoning; ASPCA APCC Toxicology Brief — cholecalciferol poisoning.

    How long after eating vitamin d will my dog show symptoms?▾

    Early signs may include often no signs yet, vomiting in the first hours. Between 2 and 12 hours, watch for loss of appetite, increased thirst and urination. Some effects can appear 12–72 hours later. Calcium and kidney changes can keep developing for days; Merck Veterinary Manual notes vets look for normal calcium and phosphorus 72–96 hours after eating before ruling out poisoning. If in doubt, call your vet.

    Should I make my dog vomit?▾

    Never induce vomiting without veterinary advice. For some substances, vomiting causes additional injury or aspiration. Call your vet or the ASPCA Animal Poison Control Center at (888) 426-4435 first.

    What will the vet do if my dog ate vitamin d?▾

    Your vet will assess your dog, may decontaminate if appropriate, and provide supportive care such as fluids, medications and monitoring. Bring the packaging or a photo of what was eaten.

    Is a daily multivitamin dangerous?▾

    Usually not — doses in standard multivitamins are low. High-strength vitamin D3 capsules (5,000–50,000 IU) are the concern.

    Why does my vet want repeat blood tests?▾

    Calcium can rise over 1–3 days, so vets often recheck calcium and kidney values daily.

    References

    Related toxins

    Also compare

    rat poisoniron supplementsbromethalinmelatonin

    Keep reading

    This is educational information, not veterinary advice. Individual dogs react differently based on health history, medications, age, and other factors this tool cannot know. When in doubt, contact your nearest veterinarian or emergency animal hospital.