Thus, in this study, our objective was to determine the serum levels of vitamin A (retinol), vitamin D (25-hydroxy vitamin D3 or 25OHVD3), and Zn in dogs with visceral leishmaniasis and to assess in vitro the ability of these nutrients to regulate the production of nitric oxide (NO), reactive oxygen species (ROS), and cytokines; regulate the adaptive responses of IFN-γ, TNF-α, and IL-10; and monitor the parasite load in CanL. This evidence concerns the gene IL10 and visceral leishmaniasis.