This study was carried out to investigate the effects of calcium (Ca) and vitamin D (V.D) intakes in post weaning rats on later adiposity outcomes. Feed intake (FI), body weight gain % (BWG%), organs weight (OW) / body weight (BW) %(OW/BW%), peritoneal fat pad% (PFP %) in post weaning rats, serum glucose ,and leptin level were studied. A total of 66 male albino rats of Sprague Dawley strain, 25 days of age weighing 40±5g were used in this study. The rats were divided into two main groups: The first main group (6 rats) was fed on abasal diet (BD) and used as a control negative group (-ve).
 
The second main group(60 rats) was divided into (10 subgroups), one of them (6rats fed on BD) and considered as control positive (+ve) group. The other (9 subgroups) were fed on (BD) containing different levels (50, 150, and 200%) from calcium, vitamin D, and calcium plus vitamin D, for 8 weeks, followed by second 8 weeks' rats were fed on a high- fat diet (HFD) as the following. The positive control group (+ve) shift up to feed only on (HFD), while the other (9subgroups) were fed on (HFD) containing the same previous levels (50, 150 & 200%) from Ca,Vit.D, and Ca plus Vit D.
 
At the end of the experiment, rats were sacrificed, and the peritoneal fat pad, liver, and kidney were then removed and weighed Blood samples were collected, then serum was separated, leptin and glucose levels were determined. The obtained results revealed that feeding the early post weaning rats for the first8 weeks on (BD) containing 50% of Ca, vitamin D & calcium plus vitamin D requirements  followed by second 8 weeks fed on (HFD) containing the same low-levels from Ca, Vit. D and Ca plus V.D caused a significant increase in feed intake, body weight gain % , peritoneal fat pad % , organs weight / body weight % , and a significant increase in Leptin and blood glucose level, while supplementation with Ca, Vit.D and Ca plus Vit. D showed a significant decrease in postweaning rats later adiposity outcome and a significant decrease in serum leptin hormone and glucose levels .