Nutrition Questions and Answers – Page 3

Calcium is the most abundant mineral in the human body, with about 99% stored in bones and teeth. Iron, zinc and iodine are essential trace minerals present in much smaller quantities.

Correct answer: Thyroid gland. Iodine deficiency reduces thyroid hormone production and can stimulate enlargement of the thyroid gland, producing goitre. Adequate iodine is especially important during pregnancy and childhood for normal brain and nervous-system development. The pituitary, adrenal gland and pancreas have different hormonal functions and do not form nutritional iodine-deficiency goitre. The distractors are related to nutrition, but each describes a different nutrient, function, energy value or deficiency condition.

Iron deficiency is the most common nutritional cause of anaemia because iron is essential for haemoglobin synthesis. Iron-deficiency anaemia commonly causes fatigue, pallor, reduced work capacity and microcytic hypochromic red cells. Calcium primarily supports bone and signalling, iodine thyroid hormone and zinc enzymes, growth and immunity. The distractors are related to nutrition, but each describes a different nutrient, function, energy value or deficiency condition. A good solution identifies the key physiological clue and then checks every option against established nutritional science.

Correct answer: Vitamin K. Vitamin K is required for hepatic synthesis and activation of several clotting factors. Vitamin A supports vision, vitamin C collagen synthesis and vitamin B12 blood-cell formation and nerve function, but none is the principal clotting vitamin.

Vitamin D deficiency in children causes rickets, characterised by defective mineralisation of growing bones. Vitamin D supports calcium and phosphate absorption; severe deficiency may cause bowed legs, bone pain and growth delay. Osteomalacia is the corresponding adult bone disorder, anaemia usually concerns haemoglobin or micronutrients, and kwashiorkor is severe protein malnutrition. The distractors are related to nutrition, but each describes a different nutrient, function, energy value or deficiency condition.

Vitamin C deficiency causes scurvy because collagen synthesis becomes defective. Rickets is linked to vitamin D, goitre to iodine and pellagra to niacin deficiency. The distractors are related to nutrition, but each describes a different nutrient, function, energy value or deficiency condition.

Thiamine deficiency causes beriberi and may also produce Wernicke–Korsakoff syndromes in high-risk adults. Thiamine is crucial for carbohydrate metabolism and nerve function; deficiency may affect the heart, peripheral nerves and muscles. Pellagra is caused by niacin deficiency, scurvy by vitamin C deficiency and night blindness by vitamin A deficiency. The distractors are related to nutrition, but each describes a different nutrient, function, energy value or deficiency condition.

Correct answer: Night blindness. Vitamin A deficiency impairs formation of visual pigments and classically causes night blindness, which can progress to xerophthalmia. Vitamin A also supports epithelial integrity, immunity, growth and reproduction; severe deficiency may damage the cornea. Scurvy results from vitamin C deficiency, beriberi from thiamine deficiency and rickets mainly from vitamin D deficiency. The distractors are related to nutrition, but each describes a different nutrient, function, energy value or deficiency condition.

Correct answer: 9 kcal. One gram of fat supplies approximately 9 kilocalories, making fat the most energy-dense macronutrient. Carbohydrate and protein each provide about 4 kcal per gram, while alcohol provides about 7 kcal but is not an essential nutrient. Four kcal applies to carbohydrate and protein; seven applies to alcohol; twelve is not the standard physiological fuel value. The distractors are related to nutrition, but each describes a different nutrient, function, energy value or deficiency condition.

Carbohydrates are the body’s principal readily available energy source and are broken down mainly into glucose. Glucose fuels the brain, muscles and other tissues; excess glucose can be stored as glycogen in liver and muscle. Protein is primarily needed for structure and repair, while vitamins and minerals regulate processes without providing calories. The distractors are related to nutrition, but each describes a different nutrient, function, energy value or deficiency condition. A good solution identifies the key physiological clue and then checks every option against established nutritional science.