Animal Pharmacological Effects of 24R,25­ Dihydroxyvitamin D3 One of the Endogenous Substances Regulating Calcium Metabolism

Lewis lung carcinoma was found to cause hypercalcaemia in tumour-bearing mice. 24R,25-Dihydroxyvitamin D3, a naturally occurring steric epimer, significantly prolonged the survival time of mice with Lewis lung carcinoma. It also had an analgesic effect in mice with Lewis lung carcinoma and increased the strength of bone weakened by the carcinoma which causes abnormal calcium metabolism and results in hypercalcaemia.