Nordic Naturls Pet Cod Liver Oil is derived from wild Arctic cod (Skrei), form the Norwegian Sea. Cod Liver Oil is an ideal source of omega-3 fatty acids and vitamin A. Pet Cod Liver Oil promotes your pet's immune health, skin and coat health, heart health and brain and eye development. Vitamin A supports normal vision, and cellular differentiation. Seasonal variations make the amount of Vitamin A fluctuate with each batch. Always refer to product label for the most up to date information.