© Stuart M Bennett 2002


Whilst only naming Cholecalciferol, otherwise known as Vitamin D3, as the title for this page, also used is ergocalciferol (Vitamin D2). Both are of a similar nature, in fact there are about ten compounds which are in the vitamin D group ( back to Cholecalciferol). These rodenticides act by causing vitamin D toxicosis, raising serum calcium levels to dangerously high levels. Clinical signs arise within 18 to 36 hours after ingestion, and include depression, anorexia, increased urination and increased water intake. Muscles are affected by high calcium, and the animal becomes very weak. Heart conduction becomes slowed, and ventricular fibrillation and cardiac arrest may result. Type of formulationsof rodenticide: granular (0.075% bait)

Other sources of Vitamin D are:

Chemical Name: Cholecalciferol; Activated 7-dehydrocholesterol.

Other Names: Calciol; (5Z,7E)-(3S)-9,10-Secocholesta-5,7,10(19)-trien-3-ol; 9,10-secocholesta-5,7,10(19)-trien-3beta-ol; oleovitamin d3; CC; duphafral d3 1000; delsterol; Deparal; ebivit; neo dohyfral d3; provitina; ricketon; trivitan; d3-vicotrat; vi-de-3-hydrosol; vigantol; vigorsan; 5,7-cholestadien-3betal-ol; 7-dehydrocholesterol; (3beta, 5Z, 7E)-9,10-secocholesta-5,7,10(19)-trien-3-ol; Dehydrocholesterol; Secocholesta-5,7,10(19)-trien-3-ol, (3beta,5Z,7E)-; Cholealciferol; Colecalciferol; Vitamin D3, crystalline.

Chemical Formula: C27H44O

Chemical Structure:


Currently available toxicology studies on Vitamin D3 are as follows:
Oral LD50 in rats: 352 mg/kg and 42 mg/kg for males, and 619 mg/kg for females.
Dermal LD50 in rabbits: 2000 mg/kg.
Primary dermal irritation: not required because technical is a solid resin.
Primary eye irritation: not required because technical is a solid resin.
Inhalation LC50: not required because technical is a solid resin.
Acute, 60-day, delayed toxicity study in rats: Acute dose, equal to accidental exposure. produced no elevated serum calcium levels and no abnormal long bone growth in young rats.
Teratology in rats: not required because technical is a solid resin and Vitamin D3 is a dietary supplement in the adult female diet.
Adequate studies are available to assess the acute toxicological effects of Vitamin D3.
No toxicological hazards of concern have been identified in the studies reviewed for this new pesticide.

Ecological Characteristics: Based on studies available to assess hazards to wildlife and aquatic organisms, Vitamin D3 is characterized as being of low toxicity to birds, because the chemical is virtually insoluble in water. Results of currently available studies are as follows: - avian oral LD50: >2000 mg/kg (mallard duck) - avian dietary LC50: 4000 ppm (mallard duck), 2000 ppm (bobwhite quail) - fish LC50: not required because technical is virtually insoluble in water - aquatic invertebrate LC50: not required because technical is virtually insoluble in water.

Clinical Signs:

The most common clinical signs associated with cholecalciferol intoxication depend on the body system that is affected. Clinical signs appear within 12- 36 hours after ingestion and include:

As the disease progresses additional clinical signs may include hypertension, polyuria, and polydipsia.

Elevated serum calcium may cause cardiac arrythmias. Calcification of cardiac and renal tissues may lead to organ failure. The clinical signs are not specific for cholecalciferol intoxication, but may be seen with other causes elevated serum calcium.

Mechanism of Action:  

Cholecalciferol increases the serum calcium concentrations by: increasing GI absorption of phosphorus and calcium, increasing osteoclastic resorption, and increasing distal renal tubular reabsorption of calcium.  


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