Which vitamin deficiency causes Night Blindness (Nyctalopia) and Keratomalacia (Xerophthalmia)?
Answer and explanation
Correct answer: A. Vitamin A
- Step 1: 11-cis-retinal is the prosthetic chromophore of rhodopsin in rod photoreceptors of the retina. Step 2. Vitamin A deficiency impairs rhodopsin regeneration, causing night blindness, and leads to corneal ulceration and xerophthalmia. Answer: Vitamin A (Retinol). Why not the others: Vitamin B1 deficiency causes beriberi; Vitamin B12 deficiency causes pernicious anemia; Vitamin E deficiency causes hemolytic anemia and ataxia.
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