Decrease in blood lead levels by vitamin c among school going adolescents of Karachi- a cluster randomized control trial

In this study we want to assess the effects of Vitamin C (Ascorbic Acid) on decreasing the blood lead levels in adolescent’s age 13-18 years. A cluster Randomized control trial will be used to conduct the the study. We hypothesize that there will be at least two units (mg/dl) difference between the two intervention groups. The purpose of this study is to investigate the role of ascorbic acid in minimizing the lead toxicity by decreasing the blood lead levels and to provide an economical and convenient and safe method of ameliorating the adverse effects of lead in developing countries. Thus a minimum 3 cluster per group will be enough to detect this difference with 90 % power. We will give vitamin C in two groups. Each school (cluster) will be given one treatment only. These school are selected from different areas (Industrial/ commercial and residential). We will collect a blood sample and fill a questionnaire to assess the lead exposure at base line. They will be then given Vitamin C for 4 weeks. After 4 weeks we will collect the second blood sample to assess the decrease in blood levels. We will also assess their dietary vitamin C intake at the time of second blood sample through a food frequency questionnaire (FFQ).