Earliest feature of Vitamin A deficiency is

UPPSC 2022

Applied Nutrition & Dietetics

Easy

Appeared in: UPPSC 2022

Explanation

Nyctalopia, or night blindness, is the earliest functional symptom of Vitamin A deficiency.
Vitamin A is a crucial component of rhodopsin, the pigment in the retina's rod cells that allows for vision in low light.
A lack of Vitamin A impairs the regeneration of rhodopsin after exposure to bright light, causing difficulty adapting to and seeing in dim environments.
This symptom appears before any visible structural changes occur in the eye, making it the first manifestation of the deficiency.

Option A: Dryness of the conjunctiva (conjunctival xerosis) is the earliest clinical sign of Vitamin A deficiency, which is an objective finding observed by a clinician. It appears after the patient has already started experiencing the symptom of night blindness.
Option C: Keratomalacia is a severe, late-stage, and irreversible complication of Vitamin A deficiency, characterized by the softening and liquefaction of the cornea. It is a medical emergency and not an early feature.
Option D: Hyphema is the presence of blood in the anterior chamber of the eye. It is completely unrelated to Vitamin A deficiency and is typically caused by blunt trauma, surgery, or specific vascular abnormalities in the iris.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Early signs and symptoms of Vitamin A deficiency as background academic context rather than a clinical decision trigger.
Early recognition of nyctalopia by a nurse is critical, as it is a reversible condition with timely Vitamin A supplementation, preventing progression to permanent blindness.
Nurses play a key role in public health by educating mothers to recognize night blindness in their children (e.g., a child who can't find their way in the evening) and seek prompt treatment.
In India, the National Programme for Prevention and Control of Blindness includes prophylactic high-dose Vitamin A supplementation for children aged 9 months to 5 years, a key nursing responsibility at immunization clinics.

How to Approach the Question

First, identify the core concept of the question, which is the 'earliest feature' of 'Vitamin A deficiency'.
This is a factual recall question that requires knowledge of the pathophysiology and clinical progression of a specific nutritional deficiency.
Recall the sequence of events in xerophthalmia. Remember that functional changes (symptoms) often precede structural changes (signs).
Evaluate each option based on this timeline. Nyctalopia is a functional symptom. Dryness of the conjunctiva is a structural sign. Keratomalacia is a late, severe complication.
Differentiate between a 'symptom' (a subjective experience, like difficulty seeing) and a 'sign' (an objective finding, like dryness). The earliest 'feature' is the first thing to occur, which is the symptom.
Eliminate unrelated options like Hyphema, which is associated with trauma, not nutritional deficiency.

Concept Tested & Keywords

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E6 Parks TextBook of Preventive & Social Medicine part 2 — Subpart A (pp 1-232 of 464) pp. 150-152, 151-153

E6 textbook of Applied Biochemistry and Nutrition & DieteticsHarbans Lal (pp 26-464 of 479) p. 361-363