Which of the following vitamins is essential for normal vision?
- (a)Folic acid
- (b)Riboflavin
- (c)Niacin
- (d)Retinol
Correct — D, Retinol. Retinol is Vitamin A. It is essential for normal vision because it combines with the protein opsin in the rod cells of the retina to form rhodopsin (visual purple), the pigment that lets the eye detect low light. A deficiency of Vitamin A first causes night blindness and, if severe, xerophthalmia and blindness.
- (a)Folic acid — Vitamin B9 — needed for DNA synthesis and red-blood-cell formation; its deficiency causes megaloblastic anaemia (and neural-tube defects), not a vision problem.
- (b)Riboflavin — Vitamin B2 — its deficiency causes cheilosis/angular stomatitis and a sore tongue; it is not the vitamin that forms the visual pigment.
- (c)Niacin — Vitamin B3 — its deficiency causes pellagra (dermatitis, diarrhoea, dementia), not the vision defect linked to Vitamin A.
Vitamin A (retinol) is a fat-soluble vitamin central to the visual cycle. In the retina it is converted to retinal, which binds opsin to make rhodopsin; light bleaches this pigment and triggers the nerve signal for sight, after which it is regenerated. Adequate Vitamin A keeps this cycle running, especially for dim-light (rod) vision. It is found in liver, dairy, eggs, and as beta-carotene in orange/green vegetables.
The trap is that three options (folic acid, riboflavin, niacin) are all B-group vitamins with familiar deficiency diseases, while 'retinol' is simply another name for Vitamin A — the one tied to the eye. Recognising retinol = Vitamin A settles the question.
- Retinol = Vitamin A; essential for the visual cycle (forms rhodopsin)
- Vitamin A deficiency → night blindness and xerophthalmia
- Riboflavin (B2) → cheilosis; Niacin (B3) → pellagra; Folic acid (B9) → megaloblastic anaemia
- Vitamin A is fat-soluble; sources include liver, dairy and beta-carotene-rich vegetables
Only Retinol (Vitamin A) is the vitamin essential for normal vision.
- Not recognising 'retinol' as another name for Vitamin A
- Mixing up which B-vitamin causes which deficiency (pellagra vs cheilosis vs anaemia)
Vitamins are asked as 'which vitamin does X' or as vitamin-to-deficiency matching; lock retinol = Vitamin A = vision/night blindness.
Consider the following pairs : Vitamin — Deficiency disease 1. Vitamin C : Scurvy 2. Vitamin D : Rickets 3. Vitamin E : Night blindness Which of the pairs given above is/are correctly matched?
- (a) 1 and 2 only
- (b) 3 only
- (c) 1, 2 and 3
- (d) None
Answer(a) 1 and 2 only
Same concept — night blindness is caused by Vitamin A deficiency (not Vitamin E), reinforcing retinol/Vitamin A's role in vision.
Consider the following statements: 1. Non-function of lachrymal gland is an important symptom of deficiency of Vitamin A. 2. Deficiency of Vitamin B1 can lead to indigestion and heart enlargement. 3. Vitamin C deficiency can lead to pain in the muscles. 4. Deficiency of Vitamin D causes increased loss of Ca++ in urine. Which of these statements given above are correct?
- (a) 1 and 2
- (b) 2, 3 and 4
- (c) 1, 3 and 4
- (d) 1, 2, 3 and 4
Answer(a) 1 and 2
Same concept — links Vitamin A deficiency to eye problems (xerophthalmia / lachrymal-gland involvement), i.e. Vitamin A's role in the eye.
- practice — not a real PYQ
Deficiency of which vitamin primarily causes night blindness?
- (a)Vitamin C
- (b)Vitamin A
- (c)Vitamin D
- (d)Vitamin K
Answer(b) Vitamin A (retinol) — needed to form the visual pigment rhodopsin.
- practice — not a real PYQ
Which of the following is the chemical name of Vitamin A?
- (a)Thiamine
- (b)Ascorbic acid
- (c)Retinol
- (d)Calciferol
Answer(c) Retinol — Vitamin A (calciferol is Vitamin D, ascorbic acid is Vitamin C).