A randomized double-blind clinical trial will be performed in the neonatal intensive care unit of Makassed General Hospital in Beirut, Lebanon from December 2021 till August 2022. Randomized opaque envelopes to allocate the treatment will be used. The study will include neonates aged between 26 and 42 gestational weeks, who require phototherapy in the neonatal intensive care unit. Patients will be randomized into two groups.Both groups will receive standard conventional phototherapy, but the intervention group will receive 10 mg per day oral zinc sulfate until discharge.

Inclusion Criteria:

• Infants (post-menstrual age ≥ 26 weeks) delivered by Cesarean section or vaginal delivery.
• Diagnosed to have hyperbilirubinemia:

Hyperbilirubinemia is defined as:

• for term and near-term neonates (neonates less than 35 weeks' gestation): Serum Total Bilirubin (STB) level that would qualify for phototherapy requirement as described in American Academy of Pediatrics 2004's guidelines or absolute STB level L 15 mg/dL;
• for preterm neonates (< 35 weeks' gestation): STB level > 1% of body weight

Exclusion Criteria:

• Infants less than 26 weeks postmenstrual age
• Allergy to zinc sulfate
• Any reaction seen after administration of first dose of zinc sulfate.
• Any contraindication to oral medication
• Infants with a history of taking phenobarbital by their mother