Calcium is an essential nutrient required for critical biological functions. Calcium supplementation is to be evaluated using immature female rats. The present study focused on some blood parameters, gonadal development and bone structure. Forty immature female Sprague-Dawley rats were randomly divided into four equal-sized groups (80 g average body weight) to receive calcium chloride dihydrate (group I: control; groups II, III and IV: received 20 mg, 40 mg and 60 mg per kg body weight, respectively) for 5 weeks. Rats were decapitated, and their trunk blood was sampled for biochemical assays. Cholesterol, triglycerides, glucose and calcium were measured. Gonadal and bone structure were histologically evaluated. Results revealed that treatment of developing female rats with three calcium doses used have no marked effect on the serum calcium and cholesterol levels. However, serum triglyceride level and body weight gain are significantly decreased in rats treated with all of the three calcium doses. Serum glucose level showed a marked increase in animals treated with the higher calcium doses. Moreover, observable histological alterations are recognized in the ovaries. Bones of the experimental animals also showed morphological alterations. These results suggest that increasing calcium supplementation decreases triglycerides and percentage body weight gain and positively affects the bone and gonadal development.