Introduction:Neonatal hyperbilirubinemia is defined as a total serum bilirubin level above 5 mg per dl (85 μmol / L). Jaundice is an important problem in the first week of life. It is a cause of concern for the physician and a source of anxiety for the parents.
Objective:The aim of this work was to measure the serum levels of vitamin B12 in neonates with indirect hyperbilirubinemia and to compare them with that of apparently healthy neonates.
Subjects and Methods:This study included 80 full term neonates divided into 2 groups: Group I: 40 full term neonates with indirect hyperbilirubinemia (23 females and 17males) aged 3-7 day's admitted to neonatal unit of Minia university hospital during the period from July to December 2017. Group II: 40 apparently healthy full term neonates as controls (20 males and 20 females) of matched age and weight.
Results:the vitamin B12 serum levels were significantly lower than in neonates with indirect hyperbilirubinemia than controls (P-value = 0.001*). No statistically significant difference regarding age, sex, mode of delivery, gestational age or weight between patients and controls as were present. Also No statistically significant difference regarding the hemoglobin levels, platelets count, WBCS count or neutrophils count between cases and controls. 
Conclusion:Full term neonates with indirect hyperbilirubinemia had lower serum levels of vitamin B12 than healthy full term neonates.