Calcitriol decreased the serum ALT levels and markedly attenuated the histological liver damage, and reduction of IFN-γ in ConA-induced hepatitis.Calcitriol inhibits CD40-induced IFN-γ and immune-modulatory activity in human monocytes and is a potent suppressor of IFN-γ-mediated macrophage activation. The gene discussed is IFNG; the disease is hepatitis A virus infection.