Randomization
Among the TUMS dormitories, two dormitories were randomly selected. First, a list of students who met the inclusion criteria was prepared, then numbers were assigned to participants. Using a random numbers table, eighty-four single female college students were enrolled in the study. Numbers 1 to 84 were divided into two groups by Randomizer statistical program. By the pharmaceutical company, one group of numbers was recorded on vitamin D packages, and the next group of numbers was recorded on placebo packages.