What are potential physical signs of vitamin A deficiency?

Vitamin A deficiency is characterized by specific physical signs, primarily night blindness and dry membranes. Night blindness occurs because vitamin A is crucial for the formation of rhodopsin, a pigment in the retina that allows for vision in low light. When the body lacks sufficient vitamin A, it cannot maintain proper visual function under dim lighting conditions.

Dry membranes, particularly the conjunctiva, which covers the eye, and the cornea, are also common signs. Vitamin A is essential for maintaining the integrity of epithelial tissues, and a deficiency can lead to xerophthalmia, which includes symptoms like dryness in the eyes and other mucous membranes.

While hyperpigmentation and skin flushing, scaliness, and peripheral neuropathy can refer to various other conditions or nutritional deficiencies, they are not recognized as primary signs associated specifically with vitamin A deficiency. Therefore, the identification of night blindness and dry membranes as key indicators of vitamin A deficiency underscores the importance of this vitamin in maintaining healthy vision and epithelial tissues.