Background & aim: Jaundice is one of the most significant problems to consider in the neonatal period. The aim of this study was to determine the impact of oral zinc sulfate on uncomplicated neonatal jaundice using comparison of effect of just phototherapy with the effect of combination of phototherapy and oral zinc sulfate.

Methods: The present double blind randomized clinical trial was carried out on 78 normal term neonates with the age of 2-7 days who were admitted for uncomplicated jaundice in neonatal ward of Imam Sajjad Hospital of Yasuj University of Medical Sciences. These infants were divided to experimental group (40 cases) and control group (38 cases) using block random allocation. In the control group, phototherapy was done alone and experimental group received elemental zinc orally as 10 mg daily for 5 days in combination with phototherapy.  The total bilirubin serum levels were measured at the beginning of the study , 6 hours, 12 hours, and 24 hours after the beginning of the study, discharge, and one week after discharge. The collected data were analyzed by the Chi Square test, independent t-test, and analysis of variance with repeated measurement.

Results: There were no significant statistical difference between the experimental group and control group in sex, age, birth weight, hemoglobin, reticulocyte percentage, G6PD deficiency, and of serum total bilirubin level at the beginning of study(p>0.05). Analysis of variance with repeated measurement showed that there were no significant statistical difference between the total bilirubin serum level at 6 hours, 12 hours, 24 hours after beginning of the study, discharge, and one week after discharge (p>0.05). Also, the mean of hospitalization duration was not significantly different between the two groups (p>0.05).

Conclusion: Although oral zinc salts inhibit the enterohepatic circulation of bilirubin, however probably not effective in the treatment of neonatal physiologic jaundice. Due to lack of human studies on the effect of oral zinc salts, further studies are recommended.