Mean ( SD ) total serum bilirubin levels in zinc and placebo groups were @ ( @ ) vs. @ ( @ ) mg/dL ( mean difference @ ; @ % CI -@ , @ , P = @ ) at @ h , @ ( @ ) vs. @ ( @ ) mg/dL ( mean difference @ ; @ % CI -@ , @ , P = @ ) at @ h and @ ( @ ) vs. @ ( @ ) mg/dL ( mean difference -@ , @ % CI -@ , @ , P = @ ) at @ h. Although the mean duration of phototherapy in the zinc group was less by @ h ( @ % CI @ , @ , P = @ ) , the difference was not significant .