Night blindness may be caused by a deficiency of which vitamin?

• A. vitamin C
• B. vitamin D
• C. vitamin A
• D. vitamin K

Answer: (C)

Night blindness is primarily caused by a deficiency of vitamin A. This vitamin plays a critical role in the formation of rhodopsin, a pigment in the retina that is essential for vision in low-light conditions. When there is insufficient vitamin A in the body, the production of rhodopsin is affected, leading to difficulties seeing in dim light, which is characterized as night blindness.

Vitamin C, vitamin D, and vitamin K are vital for various bodily functions, but they do not have a direct link to the condition of night blindness. Vitamin C is important for immune function and skin health, vitamin D is crucial for calcium absorption and bone health, and vitamin K is associated with blood clotting and bone metabolism. However, none of these vitamins are directly involved in the process of vision in low-light environments like vitamin A is. Thus, a deficiency in vitamin A specifically leads to the symptoms associated with night blindness.