to hypercalcemia since b3cd is a derivative of calcidiol a family member of calcitriol therapeutic doses of calcitriol lead to increased calcium level in blood although b3cd is a derivative of calcidiol and not calcitriol further testing of b3cd in vivo could show that b3cd may have acquired the lethal calcemic side effects of calcitriol therefore it was important to determine the effect of b3cd on serum calcium levels calcemic activity in vivo in order to establish its therapeutic potential the effect of b3cd on serum calcium levels in scid mice was tested these studies were carried out in boston university school of medicine boston mass in accordance with institutional guidelines b3cd calcidiol and calcitriol were formulated in 80 polyethylene glycol in pbs and were administered as i p injections once in 48 hours for 28 days animals were euthanized sera collected and analyzed immediately for serum calcium in the hospital core facility the animals were divided into 4 groups of 5 animals each compared with their initial weights the mean weight of mice in the control group increased by 5 4 during the 28 days of the experiment there was a drastic loss of body weight in calcitriol treated group the mice lost.