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Hypercalcemia is defined as abnormally elevated calcium levels in the blood. Of the various types of substances that are poisonous to animals, there are those that include hypercalcemic agents. Hypercalcemic agents contain vitamin D, medically known as cholecalciferol, which works by raising the calcium content in blood serum to high toxic levels, resulting in cardiac arrhythmias, and then death. Hypercalcemic agents are popular for use in rodent poisons, since rodents do not have resistance to cholecalciferol. In most cases, poisons containing cholecalciferol must be dir