Scientific Journal

Scientific Journal of the Hellenic Companion Animal Veterinary Society (HCAVS)


Hypervitaminosis D due to over supplementation: a case report

Timiou D. DVM, MSc (small animal medicine), Plakentia Veterinary Clinic, Athens
Stathopoulou V. DVM, GPCertSAM, GPCertEndo (ISVPS), PgCertSAM (HAU)
Liapis I. DVM, Cert (Ophth), Plakentia Veterinary Clinic, Athens


Vitamin D toxicosis results in increased calcium bone resorption and gastrointestinal absorption which result in hypercalcemia. We present a dog with vitamin D toxicosis due to chronic over supplementation.

Clinical case

An 8 year old, male-neutered, West Highland Terrier was presented with polyuria, polydipsia, decreased appetite and depression for 3 months. In a biochemistry profile that was submitted there were elevated renal values. The dog was receiving pancreatic enzymes, allopurinol and a multivitamin supplement prescribed in the suggested dosages. Clinical examination revealed dehydration. Complete blood count was normal, biochemistry examination revealed azotemia, elevated creatinine and hypercholesterolemia with low urine specific gravity. Calcium levels (total and ionized) were elevated. Adrenocorticotropic hormone stimulation test was negative for Addison’s disease. The imaging studies did not have relevant findings. In a later discussion, it was revealed that the owner was oversupplying vitamin D. Laboratory tests showed increased levels of vitamin D. The supplements were discontinued, and the dog was hospitalized with intravenous fluids and furosemide.


Calcium levels normalized, and the dog was discharged 48 hours later. Within one month mood and appetite gradually improved, and renal enzymes normalized.


Vitamin D toxicosis results in systematic symptoms and renal damage and must be included in the differential diagnosis of hypercalcemia.


  • Feldmanan et al. Canine and feline endocrinology 4th edition (2015).
  • Gerhard C and Jaffey JA (2020) Persistent Increase in Serum 25-Hydroxyvitamin D Concentration in a Dog Following Cholecalciferol Intoxi- cation. Front. Vet Sci 6, 472..

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