Vitamins, Minerals & Deficiency Diseases – NDA Biology PYQs

NDA 2025-I

Q. 1. Vitamin B1 is also known as

(a) Riboflavin

(b) Thiamin

(c) Retinol

(d) Tocopherol

Answer: (b) Thiamin

Explanation: Vitamin B1 is chemically known as thiamin (also spelled thiamine). It plays a key role in energy metabolism: particularly in the conversion of carbohydrates to energy: and in nerve function. Riboflavin is Vitamin B2. Retinol is Vitamin A. Tocopherol is Vitamin E. Deficiency of thiamin causes beriberi. Concept Tested: Vitamin B1 –  Thiamin; deficiency causes beriberi

★ JOVIK Exam Insight Vitamin name-synonym pairs are a common NDA topic. Key pairs: B1 –  Thiamin (beriberi). B2 –  Riboflavin. B3 –  Niacin. B12 –  Cobalamin. C –  Ascorbic acid. A –  Retinol. D –  Calciferol. E –  Tocopherol. K –  Phylloquinone.

 NDA 2024-II

Q. 2. Which one among the following diseases is caused due to deficiency of Vitamin D in humans?

(a) Beriberi

(b) Scurvy

(c) Rickets

(d) Pneumonia

Answer: (c) Rickets

Explanation: Vitamin D is essential for calcium and phosphorus absorption in the intestine and for the mineralisation of bones and teeth. Deficiency of Vitamin D in children causes rickets: a condition characterised by soft, weak, deformed bones (bow legs, knock knees). In adults, the equivalent condition is osteomalacia. Beriberi is caused by Vitamin B1 deficiency. Scurvy is caused by Vitamin C deficiency. Pneumonia is an infectious disease, not a nutritional deficiency. Concept Tested: Vitamin D deficiency causes rickets (in children) and osteomalacia (in adults)

 NDA 2021-II

Q. 3. Intestinal bacteria are main source of which one of the following vitamins?

(a) Vitamin E

(b) Vitamin C

(c) Vitamin B₁₂

(d) Vitamin A

Answer: (c) Vitamin B₁₂

Explanation: The gut microbiota (intestinal bacteria) synthesise several vitamins, including Vitamin K and Vitamin B12 (cobalamin). Vitamin B12 is produced by bacteria and is found naturally in animal products. The intestinal bacteria in the human colon produce some B12, though dietary intake from animal products remains the primary source. Vitamins A, C, and E must be obtained entirely from the diet; they are not synthesised by gut bacteria. Concept Tested: Intestinal bacteria synthesise Vitamin B12 (and Vitamin K); A, C, and E must come from diet

 NDA 2021-I

Q. 4. The major source of vitamins and minerals for vegetarians is

(a) black gram and wheat.

(b) rice and mustard.

(c) vegetables and fruits.

(d) soya bean and milk.

Answer: (c) vegetables and fruits.

Explanation: Vegetables and fruits are the richest and most diverse sources of vitamins and minerals for vegetarians. Leafy green vegetables provide iron, calcium, and folate. Fruits provide Vitamin C, potassium, and other micronutrients. Grains (wheat, rice) are primarily carbohydrate sources with limited vitamin variety. Legumes (black gram, soya bean) provide protein and some B vitamins but are not the primary source of the full range of vitamins and minerals. Concept Tested: Vegetables and fruits are the primary source of vitamins and minerals for vegetarians

 NDA 2019-II

Q. 5. Which one of the following diseases may be caused by the deficiency of vitamin C?

(a) Rickets

(b) Rabies

(c) Hepatitis

(d) Scurvy

Answer: (d) Scurvy

Explanation: Vitamin C (ascorbic acid) is essential for the synthesis of collagen: the main structural protein in connective tissue. Deficiency of Vitamin C causes scurvy, characterised by bleeding gums, skin haemorrhages, joint pain, and poor wound healing. Rickets is caused by Vitamin D deficiency. Rabies is a viral disease caused by a bite from an infected animal. Hepatitis is liver inflammation caused by viruses or toxins. Concept Tested: Vitamin C (ascorbic acid) deficiency causes scurvy

 NDA 2017-II

Q. 6. Which one of the following vitamins has a role in blood clotting?

(a) Vitamin A

(b) Vitamin D

(c) Vitamin E

(d) Vitamin K

Answer: (d) Vitamin K

Explanation: Vitamin K is essential for the synthesis of several clotting factors in the liver, including prothrombin (Factor II) and factors VII, IX, and X. Without Vitamin K, these clotting factors cannot be produced, and blood cannot clot properly: leading to excessive bleeding. Vitamin A is needed for vision and immunity. Vitamin D is needed for calcium metabolism. Vitamin E is an antioxidant. Concept Tested: Vitamin K is essential for blood clotting (synthesis of clotting factors in the liver)

★ JOVIK Exam Insight Fat-soluble vitamins A, D, E, K and their functions: A –  vision and immunity. D –  calcium absorption and bone mineralisation. E –  antioxidant. K –  blood clotting. This table is tested repeatedly by NDA.

 NDA 2015-II

Q. 7. Which one of the following vitamins is synthesized in our own skin?

(a) Vitamin A

(b) Vitamin B

(c) Vitamin C

(d) Vitamin D

Answer: (d) Vitamin D

Explanation: Vitamin D is unique among vitamins in that it can be synthesised in the skin. When ultraviolet B (UVB) radiation from sunlight strikes the skin, 7-dehydrocholesterol in the skin is converted to cholecalciferol (Vitamin D3). This is then activated in the liver and kidneys. This is why Vitamin D is sometimes called the “sunshine vitamin.” Vitamins A, B, and C cannot be synthesised in the skin. Concept Tested: Vitamin D is synthesised in the skin on exposure to sunlight (UV radiation)

 NDA 2015-I

Q. 8. Precursor of which one of the following vitamins comes from β-carotene?

(a) Vitamin A

(b) Vitamin C

(c) Vitamin D

(d) Vitamin K

Answer: (a) Vitamin A

Explanation: β-Carotene (beta-carotene) is a plant pigment that gives orange-yellow colour to carrots, sweet potatoes, and other foods. In the body, β-carotene is cleaved by an enzyme in the intestinal wall to produce two molecules of retinol (Vitamin A). β-Carotene is therefore a provitamin A: it is the dietary precursor of Vitamin A. This is why carrots are often associated with good vision (Vitamin A is needed for producing rhodopsin in the eye). Concept Tested: β-Carotene is the provitamin A: dietary precursor of Vitamin A (retinol)

 NDA 2014-I

Q. 9. After diagnosis of disease in a person, the doctor advises the patient iron and folic acid tablets. The person is suffering from

(a) osteoporosis

(b) anaemia

(c) goitre

(d) protein-energy malnutrition

Answer: (b) anaemia

Explanation: Iron and folic acid are both essential for red blood cell production. Iron is needed to synthesise haemoglobin. Folic acid is needed for DNA synthesis and the maturation of RBCs. Deficiency of either: or both: causes anaemia (insufficient or abnormal RBCs). Iron deficiency causes iron-deficiency anaemia; folic acid deficiency causes megaloblastic anaemia. Doctors prescribe iron + folic acid supplements to treat these forms of anaemia. Concept Tested: Iron + folic acid deficiency causes anaemia; doctors prescribe iron and folic acid tablets for anaemia

Q. 10. Which of the following statements about vitamins are correct?

1. Vitamin C is essential to make connective tissue in body.

2. Vitamin D is needed for synthesis of eye pigment.

3. Vitamin B12 helps in maturation of RBC.

4. Vitamin C is required to make use of calcium absorbed from the intestine.

Select the correct answer using the code given below.

(a) 1 and 2

(b) 1 and 3

(c) 2 and 4

(d) 1 and 4

Answer: (b) 1 and 3

Explanation: Statement 1 is correct: Vitamin C is essential for collagen synthesis, and collagen is the main protein of connective tissue. Statement 2 is incorrect: the eye pigment rhodopsin requires Vitamin A (retinol), not Vitamin D. Statement 3 is correct: Vitamin B12 (cobalamin) is needed for the maturation of red blood cells; deficiency causes megaloblastic anaemia. Statement 4 is incorrect: it is Vitamin D that helps the intestine absorb and utilise calcium, not Vitamin C. Concept Tested: Vitamin C → collagen (connective tissue); Vitamin B12 → RBC maturation; Vitamin D (not C) → calcium utilisation; Vitamin A (not D) → eye pigment

★ JOVIK Exam Insight NDA tests which vitamin does which function. Key facts: Vit A → rhodopsin (eye pigment). Vit C → collagen (connective tissue) and scurvy prevention. Vit D → calcium absorption and bone mineralisation. Vit B12 → RBC maturation (deficiency → megaloblastic anaemia). Vit K → blood clotting.

 NDA 2009-I

Q. 11. Among the given nutrients, milk is a poor source of

(a) Calcium

(b) Protein

(c) Carbohydrate

(d) Vitamin C

Answer: (d) Vitamin C

Explanation: Milk is an excellent source of calcium (for bones and teeth), protein (casein and whey), and carbohydrates (mainly lactose). However, milk is a very poor source of Vitamin C. The pasteurisation process and exposure to light further destroy any small amounts of Vitamin C present. Vitamin C must be obtained from fruits and vegetables. This is why infants fed exclusively on cow’s milk (without supplementation) can develop scurvy. Concept Tested: Milk is a poor source of Vitamin C; it is rich in calcium, protein, and carbohydrate

---