Which vitamin helps prevent night blindness and poor eyesight?

Vitamin A is crucial for maintaining good vision, particularly in low-light conditions. It plays an essential role in the formation of rhodopsin, a protein in the eyes that allows for the proper functioning of the retina and facilitates the ability to see in dim light. A deficiency in vitamin A can lead to night blindness, where an individual struggles to see well in the dark, and can also contribute to other vision-related issues.

The other vitamins listed play different roles in the body. Vitamin B6 is involved in protein metabolism and cognitive development, while Vitamin C is key for immune function and skin health, and Vitamin D is primarily important for bone health and calcium absorption. These vitamins, while necessary for overall health, do not directly influence the prevention of night blindness or poor eyesight in the way that vitamin A does.