Which of the following is a significant sign of vitamin A deficiency?

Corneal xerosis, which refers to the drying and clouding of the cornea, is a significant sign of vitamin A deficiency. This vitamin is essential for maintaining healthy vision, especially for the integrity of the corneal epithelium. When there is a deficiency, the production of mucous in the eyes decreases, leading to dryness and potentially severe ocular complications. Vitamin A is crucial for the proper functioning of the retina and also plays a role in the protection of epithelial tissues throughout the body, particularly in the eyes.

The presence of corneal xerosis indicates a form of keratomalacia, which can ultimately lead to blindness if left untreated. This condition highlights the importance of vitamin A in eye health and vision, and it serves as a clinical marker for assessing vitamin A status in individuals.

Other options listed, while they may signify various health issues, do not specifically relate to vitamin A deficiency in the same direct manner as corneal xerosis does. Stomatitis can be associated with several nutrient deficiencies and irritations but is not exclusive to vitamin A. Spoon nails, often indicative of iron deficiency, and pale conjunctiva, which can suggest anemia, are not signs tied to vitamin A status.