Introduction and objectiveHepatitis B virus (HBV) infection continues to be among the prominent healthcare problems around the world. e liver is a critical organ for the storage and metabolism of vitamin D. Vitamin D is known to play a role in various biological processes including cell di erentiation, cell proliferation and inhibition of immune modulation. Recently, vitamin D levels are thought to in uence the immune system and the host response in viral infections such as HBV infections. In this study, our aim is to compare the vitamin D levels in healthy individuals and those with HBV infection in order to observe the relationship between the vitamin D levels and the HBV replication and disease progression.