UPPSC 2024 Prelims GS Paper-I · Question 141 of 150

Correct — B, A-2, B-1, C-4, D-3. Each pair is one of the four classic deficiency diseases. (A) Vitamin A, chemically retinol, is the precursor of rhodopsin, the light-sensitive pigment in the rod cells of the retina. Deficiency shows first as night blindness, then as xerophthalmia — drying and clouding of the conjunctiva and cornea — and finally as keratomalacia and irreversible blindness; vitamin A deficiency remains the leading cause of preventable childhood blindness worldwide. So A goes with 2. (B) Vitamin B here means thiamine, vitamin B1, whose deficiency causes beriberi. Thiamine sits in the bran and germ of cereal grains, so a diet built on polished white rice is thiamine-poor; 'wet' beriberi damages the heart and causes oedema, 'dry' beriberi damages the peripheral nerves and wastes the muscles. So B goes with 1. (C) Vitamin C, ascorbic acid, is required for the hydroxylation step that lets the body build stable collagen. Without it connective tissue fails — bleeding and spongy gums, loose teeth, bleeding under the skin, poor wound healing — which is scurvy, the disease of long sea voyages that James Lind's citrus trials addressed in 1747. So C goes with 4. (D) Vitamin D, calciferol, controls the absorption of calcium and phosphorus from the gut, so deficiency leaves the growing bone unmineralised and soft: rickets in children, with bowed legs and a beaded rib cage, and osteomalacia in adults. So D goes with 3. A-2, B-1, C-4, D-3 is option (b). One caution on precision: the list says 'Vitamin B', but beriberi is specifically a thiamine (B1) deficiency — other B vitamins give quite different diseases, riboflavin (B2) causing cheilosis and angular stomatitis, niacin (B3) causing pellagra, and cobalamin (B12) causing pernicious anaemia.

• (a)A-4, B-3, C-2, D-1 — Reverses the list completely, giving scurvy to vitamin A, rickets to vitamin B, blindness to vitamin C and beriberi to vitamin D. Every pair is wrong. Scurvy is the vitamin C disease and rickets the vitamin D one, so this is the mirror image of the correct answer and the standard reversal decoy.
• (c)A-1, B-2, C-3, D-4 — Simply pairs A with 1, B with 2, C with 3 and D with 4 in sequence, which is the option an unprepared candidate picks by default. It gives beriberi to vitamin A, blindness to vitamin B, rickets to vitamin C and scurvy to vitamin D — all four wrong. Beware of any match option that lines the two lists up in their printed order.
• (d)A-1, B-3, C-2, D-4 — Wrong in all four pairs as well: beriberi to vitamin A, rickets to vitamin B, blindness to vitamin C and scurvy to vitamin D. It is the most plausible-looking of the three decoys because it keeps rickets in the top half of the list, but rickets is the softening of growing bone caused by lack of vitamin D and the calcium absorption that depends on it, not by any B vitamin.

Vitamins are organic micronutrients that the human body cannot synthesise in adequate amounts, so they must come from the diet; each acts as a coenzyme or a regulator in a specific pathway, and its absence produces a characteristic deficiency disease. They split into two groups. The fat-soluble vitamins A, D, E and K are stored in the liver and fatty tissue and can accumulate to toxic levels. The water-soluble ones — the B complex and vitamin C — are not stored in quantity, are excreted in urine, and must be supplied regularly, which is why their deficiency diseases appear relatively quickly on a poor diet. Vitamin D is the partial exception to the 'diet only' rule: the skin makes it from a cholesterol precursor under ultraviolet B in sunlight.

This is the most predictable question in the whole science section, and it is solved by holding four anchor pairs: A–eyes, B1–beriberi, C–scurvy, D–rickets. The examiner's only lever is to permute them, which is why all three wrong options here are wrong in every pair rather than partly right — there is no half-credit trap to fall into. Two things are worth adding so that a variant does not catch you. First, the question says 'Vitamin B' loosely; in a harder paper the option would read B1 or thiamine, and the B-complex family would be split out into riboflavin, niacin and cobalamin with their own diseases. Second, 'blindness' from vitamin A deficiency is the end of a progression that begins with night blindness and passes through xerophthalmia — UPSC has more than once tested the earlier stages rather than the word 'blindness'.

• Vitamin A (retinol; provitamin beta-carotene in plants) — needed to form rhodopsin in the retina's rod cells. Deficiency causes night blindness, then xerophthalmia and keratomalacia, and finally irreversible blindness. Fat-soluble. Sources: liver, egg yolk, milk fat, and carotene-rich vegetables such as carrot and dark green leaves.
• Vitamin B1 (thiamine) — deficiency causes beriberi. Thiamine lies in the bran and germ of the grain, so milled and polished white rice is thiamine-poor. Wet beriberi affects the heart and causes oedema; dry beriberi affects the peripheral nerves. Water-soluble.
• Vitamin C (ascorbic acid) — required for the hydroxylation of proline and lysine in collagen synthesis. Deficiency causes scurvy: bleeding, spongy gums, loose teeth, subcutaneous bleeding and poor wound healing. James Lind's shipboard trial of 1747 showed citrus fruit cured it. Water-soluble; sources include amla, guava, citrus fruit and green chilli.
• Vitamin D (calciferol) — regulates the absorption of calcium and phosphorus from the intestine. Deficiency causes rickets in children (soft, bowed leg bones, beading of the ribs) and osteomalacia in adults. Fat-soluble, and the only vitamin the human body can make for itself, in the skin from 7-dehydrocholesterol under ultraviolet B in sunlight.
• Other B-complex deficiencies to keep separate: riboflavin (B2) causes cheilosis and angular stomatitis, niacin (B3) causes pellagra with its dermatitis, diarrhoea and dementia, folate and cobalamin (B12) cause megaloblastic and pernicious anaemia. Vitamin K deficiency impairs blood clotting.

• Attaching night blindness to vitamin E instead of vitamin A. UPSC has used exactly this substitution in a pair-matching question.
• Treating 'Vitamin B' as a single substance. Beriberi is thiamine (B1); pellagra is niacin (B3) and cheilosis riboflavin (B2), and a sharper paper will name the sub-vitamin.
• Confusing rickets with osteomalacia and osteoporosis. Rickets is vitamin D deficiency in the growing child, osteomalacia the same deficiency in the adult, and osteoporosis is a loss of bone mass with a different set of causes.

UPPSC returns to vitamins almost every year, usually as a four-by-four match or a single 'which vitamin causes / which vitamin is present in' question; UPSC prefers 'consider the following pairs — which is/are correctly matched', slipping one wrong pair such as vitamin E with night blindness into an otherwise correct list.

• practice — not a real PYQ

  Which one of the following is the only vitamin that the human body can synthesise for itself, and where?

  • (a)Vitamin A, in the liver
  • (b)Vitamin C, in the kidneys
  • (c)Vitamin D, in the skin under ultraviolet light
  • (d)Vitamin K, in the retina

  Answer(c) Vitamin D, made in the skin from 7-dehydrocholesterol on exposure to ultraviolet B in sunlight. The liver stores vitamin A but does not create it; humans cannot make vitamin C at all, unlike most other mammals; vitamin K is largely supplied by gut bacteria, not by the retina.

• practice — not a real PYQ

  Consider the following pairs — Vitamin : Deficiency disease. 1. Riboflavin : Pellagra 2. Niacin : Cheilosis 3. Ascorbic acid : Scurvy. Which of the pairs given above is/are correctly matched?

  • (a)1 and 2 only
  • (b)3 only
  • (c)2 and 3 only
  • (d)1, 2 and 3

  Answer(b) 3 only. Ascorbic acid is vitamin C and its deficiency causes scurvy. Pairs 1 and 2 are swapped: riboflavin (B2) deficiency causes cheilosis and angular stomatitis, while niacin (B3) deficiency causes pellagra.