Question 1

Which of the following statements best explains why fat-soluble vitamins can accumulate to toxic levels in the body, while water-soluble vitamins generally do not?

Accepted Answer

Fat-soluble vitamins are stored in the liver and adipose tissue, while water-soluble vitamins are excreted in urine.

Question 2

A patient presents with night blindness and dry, scaly skin. Which vitamin deficiency is most likely responsible, and what is a classic food source to recommend?

Accepted Answer

Vitamin A deficiency; recommend liver or carrots.

Question 3

Which of the following best describes the role of antioxidants such as vitamins A, C, and E in the body?

Accepted Answer

They neutralize free radicals, reducing oxidative stress and lowering the risk of chronic diseases.

Question 4

A person following a strict vegan diet is at greatest risk for deficiency of which vitamin, and why?

Accepted Answer

Vitamin B12, because it is only naturally found in animal foods.

Question 5

Which vitamin is essential for the synthesis of four blood clotting factors and is also important for bone health?

Accepted Answer

Vitamin K

Question 6

A patient with a history of alcoholism presents with confusion, loss of coordination, and rapid heartbeat. Which vitamin deficiency is most likely, and what is the classic disease called?

Accepted Answer

Thiamin (B1) deficiency; Wernicke-Korsakoff syndrome

Question 7

Which of the following best explains why folic acid supplementation is recommended for women of childbearing age?

Accepted Answer

It reduces the risk of neural tube defects such as spina bifida in the developing fetus.

Question 8

A patient is prescribed high-dose niacin to lower LDL cholesterol. Which adverse effect should they be warned about?

Accepted Answer

Flushing of the skin

Question 9

Which vitamin requires intrinsic factor for absorption, and what condition results from its deficiency due to lack of intrinsic factor?

Accepted Answer

Vitamin B12; Pernicious anemia

Question 10

Which of the following is a correct statement about vitamin D metabolism?

Accepted Answer

Vitamin D is converted to its active form in the kidneys after initial conversion in the liver.

Question 11

A patient presents with dermatitis, diarrhea, dementia, and death. Which vitamin deficiency is most likely, and what is the name of this condition?

Accepted Answer

Niacin (B3) deficiency; Pellagra

Question 12

Which of the following best describes the function of water-soluble B vitamins as coenzymes?

Accepted Answer

They assist enzymes in catalyzing metabolic reactions by binding to the enzyme and substrate.

Question 13

Which vitamin deficiency is associated with macrocytic anemia and can be masked by excessive intake of its synthetic form?

Accepted Answer

Vitamin B12 deficiency masked by excess folic acid

Question 14

A patient is taking warfarin (an anticoagulant). What is the most important dietary advice regarding vitamin K?

Accepted Answer

Keep vitamin K intake consistent to avoid altering drug effectiveness.

Question 15

Which of the following is a symptom of vitamin C deficiency, and what is the name of the disease?

Accepted Answer

Bleeding gums and poor wound healing; Scurvy

Question 16

Which vitamin is most likely to be destroyed by exposure to air, water, or heat during cooking, and what is a recommended method to preserve it?

Accepted Answer

Vitamin C; steam or microwave vegetables with minimal water

Question 17

A patient consumes large amounts of raw egg whites daily and develops hair loss, skin rash, and fatigue. Which vitamin deficiency is most likely, and what is the mechanism?

Accepted Answer

Biotin deficiency; avidin in raw egg whites binds biotin, preventing absorption

Question 18

Which of the following is a provitamin that can be converted to an active vitamin in the body, and what is its active form?

Accepted Answer

Beta-carotene; converted to vitamin A (retinol)

Question 19

Which vitamin acts as a hormone to regulate calcium and phosphorus metabolism, and what disease results from its deficiency in children?

Accepted Answer

Vitamin D; Rickets

Question 20

A patient presents with nerve problems, muscle weakness, and increased oxidative damage to cell membranes. Which vitamin deficiency is most likely?

Accepted Answer

Vitamin E deficiency

Vitamins: Functions, Sources, and Health Implications

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