INS and Insulin resistance: The mean levels of HOMA in group 1 and mean levels of QUICKI in group 2 were significantly higher than in other groups. The percentage and the mean diameters of the dominant follicles were higher in group 2 than in group 1. Also, group 2 showed lower rate of irregular menstruation after treatment than group 1 but without significant difference. Therefore calcium and vitamin D plus metformin are useful in treatment of PCOS via modifying insulin and causing decreased insulin resistance and increased insulin sensitivity.