ANSC Feeds Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

Vitamin A is essential for both vision and immune function in animals. It plays a critical role in the formation of retinal, a component of the visual pigment rhodopsin, which is necessary for the detection of light and color in the eyes. This is particularly important for night vision and overall eye health.

In addition to its role in vision, Vitamin A is vital for the immune system. It helps maintain the integrity of mucosal surfaces and contributes to the normal functioning of immune cells. A deficiency in Vitamin A can lead to a weakened immune response, increasing susceptibility to infections.

Other vitamins listed have important functions as well, but they do not serve the same dual purpose in vision and immune health as Vitamin A does. For instance, Vitamin C is more closely associated with antioxidant functions and collagen synthesis, Vitamin B12 is primarily involved in red blood cell formation and neurological function, and Vitamin D is crucial for calcium metabolism and bone health. Thus, the multifaceted role of Vitamin A in both vision and immune function makes it the correct answer in this context.