Hypercalcemia and hypervitaminosis D had been postulated as a cause of renal stones In Children ". Several studies and meta analysis had clearly shown correlation between high serum vitamin D and renal stones. Vitamin D is important for development of bones in children. Deficiency of vitamin D can lead to hypocalcemia, bone demineralisation , Rickets and growth retardation. There is high prevalence of Vitamin D deficiency in India and more so in hilly areas. Prevalence of renal stones is also higher in these areas. This is in contrast to common finding of high vitamin D and calcium levels in stone formers.This study will be conducted to determine the levels of vitamin D and serum calcium levels in children with renal stones. Further in patients of Vitamin D deficiency repletion of vitamin D will be done and effects will be noted after 3 months. Kidney stones are common, with an estimated prevalence of about 10% in the US population.1 Higher urine calcium excretion is a major risk factor for calcium stone formation,which in turn might be increased by higher circulating levels of 1,25–dihydroxyvitamin D (1,25[OH]2D). In a prospective nested case–control study, the odds of kidney stones were 73% higher for those in the highest quartile of 1,25[OH]2D.5 The association between precursors of 1,25[OH]2D such as circulating 25–hydroxyvitamin D (25[OH]D) and intake of cholecalciferol (vitamin D3) and ergocalciferol (vitamin D2) is less clear. Material and Methods This study will be conducted In 50 patients coming In surgery 0P0 with renal stones/concretions/ nephrollthiasls. Inclusion criteria 1. Age between 15–50 years . 2. Unilateral or bilateral stones. Exclusion criteria. 1. Anatomncal abnormalities nice PUJO. horse shoe kidney. 5 shaped kidney 2. Metabolic abnormalities which cause hyperoxaluria, hypercalciurla. Aim 1. To study the levels of vitamin D and calcium in patients of renal stones 2 . To treat hypovitaminosis if present and to study Its effects on renal stones Summary and conclusion There is growing evidence that cholecalciferol administration , in the higher ranges, may increase urinary calcium excretion and kidney stone formation in predisposed individuals or specific groups of patients , the observation of an association between “low” levels of circulating vitamin D serum levels and a broad spectrum of diseases has been at the origin of a dramatical increase in the prescription of vitamin D.