NBEO Biochemistry Practice Exam 2025 – The Comprehensive All-in-One Guide to Exam Success!

Night blindness and Bitot's spots are both clinical manifestations associated with a deficiency of vitamin A. This vitamin is crucial for maintaining proper vision, particularly in low-light conditions. Vitamin A is a key component of rhodopsin, a pigment in the retina that is essential for night vision. When there is a deficiency, the production of rhodopsin is impaired, leading to difficulty seeing in dim light, commonly referred to as night blindness.

Bitot's spots, which are foamy, white lesions on the conjunctiva of the eyes, are specifically linked to vitamin A deficiency and indicate damage to the conjunctival epithelium due to a lack of this vitamin. Vitamin A plays a vital role in maintaining the integrity and health of epithelial tissues, including those in the eyes.

Other vitamins listed, such as the B vitamins, vitamin E, and vitamin D, do not have direct associations with night blindness or the appearance of Bitot's spots. This highlights the unique role that vitamin A plays in visual health and its importance in preventing conditions related to its deficiency.