Cholecalciferol is main ingredient in rat poison. It is in vitamin D3. Is vitamin d3 safe?

At high doses cholecalciferol is poisonous. Rodents are somewhat more susceptible to high doses than other species, and cholecalciferol has been used in poison bait for the control of these pests. It has been claimed that the compound is less toxic to non-target species. However, in practice it has been found that use of cholecalciferol in rodenticides represents a significant hazard to other animals, such as dogs and cats. "Cholecalciferol produces hypercalcemia, which results in systemic calcification of soft tissue, leading to renal failure, cardiac abnormalities, hypertension, CNS depression, and GI upset. Signs generally develop within 18-36 hr of ingestion and can include depression, anorexia, polyuria, and polydipsia.

The LD50 is 16.8 mg/kg, but only 9.8 mg/kg if calcium carbonate is added to the bait.Kidneys and heart are target organs.

One gram of pure vitamin D3 is 40 000 000 (40x106) IU, where one IU is equivalent to 0.025 μg. "Recommendations are: 5 micrograms (200 IU or International Units) daily for all individuals (males, female, pregnant/lactating women) under the age of 50 years-old. For all individuals from 50-70 years-old, 10 micrograms daily (400 IU) is recommended. For those who are over 70 years-old, 15 micrograms daily (600 IU) is suggested. The upper limit (UL) for vitamin D has been recommended as 2,000 IU daily due to toxicities that can occur when taken in higher doses. Patients with severe vitamin D deficiency will require treatment with a loading dose, its magnitude can be calculated based on the actual serum 25-hydroxy-vitamin D level and body weight.

Also, there is a therapy for rickets utilizing a single dose, called stoss therapy in Europe - taking from 300 000 IU (7500 μg) to 500 000 IU (12 500 μg), as a single dose, or two to four divided doses.

The 25-hydroxy vitamin D (calcifediol) blood test is used to determine how much vitamin D is in the body. The normal range of calcifediol is 30.0 to 74.0 ng/mL.

"Vitamin D toxicity can result from regular excess intake of this vitamin, and may lead to hypercalcemia and excess bone loss. Individuals at particular risk include those with hyperparathyroidism, kidney disease, sarcoidosis, tuberculosis, or histoplasmosis. Chronic hypercalcemia may lead to serious or even life-threatening complications, and should be managed by a physician. Early symptoms of hypercalcemia may include nausea, vomiting, and anorexia (appetite/weight loss), followed by polyuria (excess urination), polydipsia (excess thirst), weakness, fatigue, somnolence, headache, dry mouth, metallic taste, vertigo, tinnitus (ear ringing), and ataxia (unsteadiness). Kidney function may become impaired, and metastatic calcifications (calcium deposition in organs throughout the body) may occur, particularly affecting the kidneys. Treatment involves stopping the intake of vitamin D or calcium, and lowering the calcium levels under strict medical supervision, with frequent monitoring of calcium levels. Acidification of urine and corticosteroids may be necessary.

However, for more details please do talk to a doctor/pharmacist, take care.