Vitamins and Minerals Questions and Answers

Answer: A

The mineral is Selenium.

Keshan disease is a cardiomyopathy first described in the Keshan region of China, where soils are poor in selenium. Selenium is part of the enzyme glutathione peroxidase, which protects cells from oxidative damage, and deficiency also impairs immune function. Selenium supplementation prevented the disease.

Chromium deficiency impairs glucose tolerance, fluoride deficiency raises the risk of dental caries, and zinc deficiency causes growth retardation, poor wound healing and impaired immunity, but none of them causes Keshan disease.

Answer: D

The keyed answer is 1, 3 and 4: copper, zinc and iron.

A metalloenzyme has a metal ion bound in its structure that it needs to work. The classical human examples are zinc (carbonic anhydrase, alcohol dehydrogenase), copper (cytochrome c oxidase, superoxide dismutase, tyrosinase) and iron (catalase, the cytochromes). These three trace elements are the ones nutrition texts name together.

Nickel (2) is found in a few enzymes such as urease in plants and bacteria, but it is not counted among the metals of human metalloenzymes in the usual lists, which is why the options containing it are wrong. Option A leaves out iron, and no option offers all four metals, so 1, 3 and 4 is the best fit.

Answer: D

The correct match is a-III, b-I, c-IV, d-II.

• Tocopherol is vitamin E.
• Phylloquinone (spelt 'phylloquinine' in the paper) is vitamin K₁, the plant form of vitamin K.
• Retinol is vitamin A.
• Cyanocobalamin is vitamin B₁₂, which contains cobalt.

The first option swaps K₁ and B₁₂, and the other two misplace tocopherol, so only the fourth puts every chemical name with its vitamin.

Answer: C

Vitamins are classified as both fat soluble and water soluble.

The fat-soluble vitamins are A, D, E and K; they are absorbed with dietary fat and stored in the liver and fatty tissue. The water-soluble vitamins are the B-complex vitamins and vitamin C; they are not stored in large amounts and excess is lost in urine.

Choosing only one class leaves out the other, and 'food soluble vitamin' is not a category.

Answer: B

The vitamin is vitamin C.

Vitamin C (ascorbic acid) is a powerful water-soluble antioxidant. It is needed as a cofactor for the enzymes that build collagen, which is why its deficiency, scurvy, causes bleeding gums and poor wound healing, and it also takes part in making carnitine and the neurotransmitter norepinephrine.

Vitamin E is also an antioxidant, but it is fat-soluble and has no role in collagen synthesis. Vitamin A is needed for vision and epithelia, and vitamin D for calcium absorption and bones.

Answer: A

Ocular lesions are caused by deficiency of vitamin A.

Vitamin A is needed to make rhodopsin, the light-sensitive pigment of the retina, and to keep the conjunctiva and cornea healthy. Its deficiency causes xerophthalmia: night blindness, dryness of the conjunctiva, Bitot's spots, and in severe cases softening of the cornea (keratomalacia) and blindness.

Vitamin K deficiency causes bleeding disorders, vitamin D deficiency causes rickets and osteomalacia, and vitamin C deficiency causes scurvy. None of these is the classic cause of eye lesions.

Answer: A

The correct statements are a, b and c.

Minerals build cells, tissues and fluids and regulate processes such as nerve transmission (a), and they are essential parts of body fluids (b). Calcium, phosphorus and magnesium are needed in relatively large amounts, as macrominerals (c).

Statement d is wrong because sodium is a macromineral, not a trace element; iodine and copper are trace elements. Statement e is reversed: iron is absorbed more easily in its ferrous (Fe2+) form than in its ferric form, which is why vitamin C, which keeps iron reduced, aids absorption.

Answer: A

The correct matching is a-III, b-I, c-IV, d-II.

• Retinol is vitamin A (III).
• Cholecalciferol is vitamin D3 (I).
• Tocopherol is vitamin E (IV).
• Cobalamin is vitamin B12 (II).

Option B pairs the lists in printed order, which would make retinol vitamin D. Cobalamin is the only vitamin containing cobalt, which gives it its name.

Answer: C

The water-soluble vitamin is vitamin B complex.

The B vitamins (such as thiamine, riboflavin, niacin, folate and B12) and vitamin C dissolve in water. Except for B12, they are stored in the body only in small amounts, so they are needed regularly in the diet, and excess is lost in the urine.

Vitamins A, D, E and K are fat-soluble: they are absorbed with dietary fat and stored in the liver and fatty tissue.

Answer: B

The answer is Both A and R are correct but R is not the correct explanation of A.

The Assertion is true: sodium, chloride and potassium maintain the correct concentration and balance of the body fluids, and chloride is needed to make hydrochloric acid in the gastric juice.

The Reason is also true: these minerals are eaten mainly as common salt (sodium chloride) and as potassium chloride, and occur naturally in fish and many other foods. But the Reason only says where the minerals come from; it does not explain why the body needs them, so it is not the explanation of A.