The toxic nature of lead has been recognized ubiquitous for than 2,000 years and today it is a persistent and common environmental contaminant in most parts of the world. Vitamin C is a strong antioxidant and a metabolic co factor playing an important role in many biological processes and biochemical functions (hydroxylation reactions). The research objective is to assess the effect of oral ascorbic acid supplementation 500mg and 250 mg once a day for 4 weeks on Blood Lead level among school going urban adolescents, using a cluster randomized trial study design. Ascorbic Acid (vitamin C) 250 and 500 mg will be administered in two study arms.