Vitamins & Minerals — Set 1

Correct Answer: C. Vitamin D

• **Vitamin D** = When ultraviolet B (UVB) rays from sunlight hit the skin, they convert a cholesterol compound (7-dehydrocholesterol) into Vitamin D3, making it the only vitamin the body manufactures through sun exposure. • **Unique dual source** — Vitamin D can come from both sunlight and diet (fatty fish, egg yolk, fortified foods), unlike all other vitamins which must come exclusively from food. • Deficiency in sunlight-deprived populations (night-shift workers, women in full covering) is a major public health concern. • 💡 Option A (Vitamin A) is wrong because it is obtained from food sources like carrots and liver, not synthesized by sunlight; Option B (Vitamin B12) is wrong because it is produced by bacteria and found in animal products, with no role for sunlight; Option D (Vitamin C) is wrong because it must be obtained from fruits and vegetables and degrades on exposure to heat and light.

Correct Answer: A. Iodine

• **Iodine** = Iodine is an essential component of the thyroid hormones T3 (triiodothyronine) and T4 (thyroxine); when iodine is deficient the thyroid gland enlarges abnormally in an attempt to capture more iodine from the blood, producing Goitre. • **Endemic Goitre** — regions far from the sea and high-altitude areas have iodine-poor soil and water, making their populations most vulnerable; iodisation of salt is the primary preventive measure. • India's National Iodine Deficiency Disorders Control Programme mandates iodised salt nationwide to eliminate this preventable condition. • 💡 Option B (Iron) is wrong because its deficiency causes anemia, not Goitre; Option C (Calcium) is wrong because its deficiency causes rickets and osteoporosis; Option D (Potassium) is wrong because potassium deficiency leads to hypokalemia affecting muscles and the heart, not the thyroid.

Correct Answer: C. Vitamin C

• **Vitamin C** = Vitamin C (ascorbic acid) dissolves readily in water and is transported in the blood plasma; because it cannot be stored in the body, excess amounts are excreted in urine, requiring daily dietary intake. • **Heat and oxidation sensitive** — Vitamin C is destroyed by prolonged cooking, exposure to air, and alkaline conditions, which is why raw fruits and vegetables are the best sources. • The B-complex group (B1, B2, B3, B6, B12, folate, biotin, pantothenic acid) and Vitamin C together form the complete list of water-soluble vitamins. • 💡 Option A (Vitamin E) is wrong because it is fat-soluble, stored in adipose tissue and the liver; Option B (Vitamin K) is wrong because it is also fat-soluble and requires dietary fat for absorption; Option D (Vitamin A) is wrong because it is fat-soluble and accumulates in the liver, where excess can cause toxicity.

Correct Answer: D. Vitamin A

• **Vitamin A** = The active form of Vitamin A in the human body is retinol, named from the Latin 'retina' because of its critical role in producing rhodopsin, the light-sensitive pigment in rod cells that enables low-light and night vision. • **Dual dietary form** — Vitamin A occurs as preformed retinol in animal products (liver, dairy, eggs) and as provitamin A carotenoids (beta-carotene) in orange and dark-green vegetables, which the body converts to retinol. • Beyond vision, Vitamin A is essential for maintaining epithelial integrity, immune function, and normal growth and reproduction. • 💡 Option A (Vitamin E) is wrong because its chemical name is tocopherol, not retinol; Option B (Vitamin K) is wrong because it is known as phylloquinone (K1) or menaquinone (K2); Option C (Vitamin D) is wrong because its active form is calcitriol.

Correct Answer: A. Iron

• **Iron** = Iron is the central atom of the haem group in haemoglobin; without adequate iron the body cannot produce enough functional haemoglobin, leading to iron-deficiency anemia — the world's most widespread nutritional disorder. • **Two dietary forms** — Haem iron from meat and fish is absorbed at 15–35%, while non-haem iron from plants is absorbed at only 2–20%; consuming Vitamin C alongside plant iron significantly boosts absorption. • Iron deficiency anemia is most common in women of reproductive age, infants, and children due to increased iron demands and blood loss. • 💡 Option B (Copper) is wrong because copper deficiency causes a rare anemia-like condition but is not the primary cause of common anemia; Option C (Zinc) is wrong because its deficiency primarily affects growth, immunity and wound healing; Option D (Magnesium) is wrong because magnesium deficiency affects muscle and nerve function, not red blood cell production.

Correct Answer: A. Vitamin K

• **Vitamin K** = Vitamin K acts as a cofactor for the enzyme gamma-carboxylase, which activates clotting factors II (prothrombin), VII, IX, and X in the coagulation cascade; without it, the blood cannot form a stable clot and even minor injuries can cause prolonged bleeding. • **'K' from Koagulation** — the letter K comes from the Danish/German word 'Koagulation', coined by Danish scientist Henrik Dam who discovered it in 1929 and won the Nobel Prize in 1943. • Newborns receive a Vitamin K injection at birth because breast milk is low in it and their gut bacteria have not yet established adequate synthesis. • 💡 Option B (Vitamin E) is wrong because it acts as an antioxidant and actually has mild anticoagulant properties; Option C (Vitamin D) is wrong because it regulates calcium absorption, not clotting; Option D (Vitamin C) is wrong because it supports collagen synthesis and wound healing but plays no direct role in the clotting cascade.

Correct Answer: C. Vitamin C

• **Vitamin C** = Scurvy results from Vitamin C (ascorbic acid) deficiency because ascorbic acid is essential for hydroxylating proline and lysine during collagen synthesis; without it, collagen fibres are weak, causing bleeding gums, loose teeth, skin haemorrhages, and poor wound healing. • **Historical significance** — Scurvy ravaged sailors on long sea voyages until James Lind's 1747 trial proved citrus fruits (lemon/lime juice) prevented and cured it, leading to the nickname 'limeys' for British sailors. • As little as 10 mg of Vitamin C per day prevents scurvy; current recommended intake is 65–90 mg/day for adults. • 💡 Option A (Vitamin B1) is wrong because its deficiency causes Beriberi, which affects the nervous system and heart; Option B (Vitamin D) is wrong because its deficiency causes Rickets in children and Osteomalacia in adults; Option D (Vitamin A) is wrong because its deficiency causes Night Blindness and Xerophthalmia.

Correct Answer: D. Amla (Indian Gooseberry)

• **Amla (Indian Gooseberry)** = Amla contains approximately 600–700 mg of Vitamin C per 100 g of fresh fruit, making it one of the richest known natural sources of ascorbic acid — roughly 20 times more than an orange and 160 times more than an apple. • **Stability advantage** — Amla's Vitamin C is more heat-stable than that in most other fruits because it is complexed with tannins, meaning it retains potency even after cooking, pickling, or drying. • Amla is the key ingredient in the traditional Ayurvedic formulation Chyawanprash and is extensively used in hair and skin products. • 💡 Option A (Milk) is wrong because milk contains negligible Vitamin C (about 1 mg/100 g) and is valued for calcium and protein instead; Option B (Apple) is wrong because it provides only about 4–6 mg/100 g of Vitamin C; Option C (Carrot) is wrong because carrots are an excellent source of beta-carotene (provitamin A), not Vitamin C.

Correct Answer: C. Calcium

• **Calcium** = About 99% of the body's calcium is stored in bones and teeth in the form of hydroxyapatite [Ca₁₀(PO₄)₆(OH)₂], a crystalline mineral that provides their rigidity and compressive strength; the remaining 1% in blood and cells regulates muscle contraction, nerve transmission, and blood clotting. • **Constant remodelling** — bones are not static; osteoblasts continuously deposit calcium while osteoclasts resorb it, a balance regulated by Vitamin D, parathyroid hormone, and calcitonin. • Adequate calcium intake throughout childhood and adolescence determines peak bone mass; low peak bone mass is the primary risk factor for osteoporosis in later life. • 💡 Option A (Sodium) is wrong because sodium maintains fluid balance and nerve function, not bone mineralisation; Option B (Chlorine) is wrong because it is a component of stomach acid (HCl) and helps maintain fluid balance; Option D (Iron) is wrong because iron is central to haemoglobin and oxygen transport, not bone or tooth formation.

Correct Answer: A. Vitamin A

• **Vitamin A** = Vitamin A is required to synthesise rhodopsin, the photosensitive pigment in the rod cells of the retina that function in dim light; deficiency depletes rhodopsin, impairing the ability to see in low-light conditions — a condition called nyctalopia (night blindness). • **Progression of deficiency** — if Vitamin A deficiency continues, it advances to Xerophthalmia (dry eyes), Bitot's spots, corneal ulceration, and ultimately irreversible blindness; it is the leading cause of preventable childhood blindness worldwide. • Dark-green leafy vegetables, orange and yellow fruits, and dairy products are the main dietary sources; beta-carotene from plants converts to Vitamin A in the intestinal wall. • 💡 Option B (Vitamin K) is wrong because its deficiency impairs blood clotting and has no connection to vision; Option C (Vitamin B) is wrong because B-complex vitamins are involved in energy metabolism and neurological function, not the visual cycle; Option D (Vitamin C) is wrong because its deficiency causes Scurvy, not any vision disorder.