Question 1

Which of the following statements best explains why water-soluble vitamins are less likely to reach toxic levels in the body compared to fat-soluble vitamins?

Accepted Answer

Water-soluble vitamins are easily absorbed and excreted in urine, so they are not stored extensively in tissues.

Question 2

A patient presents with symptoms of weakness, nerve degeneration, and heart changes. Which vitamin deficiency is most likely responsible for these symptoms, and what is the classic disease called?

Accepted Answer

Thiamin (Vitamin B1); Beriberi

Question 3

Which of the following best describes the process of enrichment as regulated by Health Canada?

Accepted Answer

Adding nutrients back to foods that lost them during processing, such as adding B vitamins to white rice.

Question 4

A vegan is at increased risk for which vitamin deficiency, and why?

Accepted Answer

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

Question 5

Which vitamin acts as a coenzyme in the conversion of tryptophan to niacin and is also involved in amino acid metabolism?

Accepted Answer

Vitamin B6 (pyridoxine)

Question 6

A patient with a diet high in raw egg whites develops a deficiency in which vitamin, and what is the mechanism?

Accepted Answer

Biotin; Avidin in egg whites binds biotin, making it unavailable for absorption.

Question 7

Which vitamin is essential for the synthesis and maintenance of collagen, and what is a classic symptom of its deficiency?

Accepted Answer

Vitamin C; Poor wound healing and bleeding gums (scurvy)

Question 8

A person with a diet lacking in niacin develops dermatitis, diarrhea, dementia, and eventually death. What is the name of this condition, and which amino acid can be used to synthesize niacin if present in the diet?

Accepted Answer

Pellagra; Tryptophan

Question 9

Which of the following statements about folate is TRUE?

Accepted Answer

Folate deficiency in early pregnancy can cause neural tube defects such as spina bifida.

Question 10

Which vitamin is required for the maintenance of the myelin sheath on nerves and for the conversion of homocysteine to methionine?

Accepted Answer

Vitamin B12 (cobalamin)

Question 11

A patient presents with macrocytic anemia, but supplementation with folic acid resolves the anemia while neurological symptoms persist. What is the most likely underlying deficiency?

Accepted Answer

Vitamin B12 (cobalamin)

Question 12

Which of the following best describes the role of antioxidants such as vitamin C in the body?

Accepted Answer

They neutralize free radicals by donating electrons, preventing cellular damage.

Question 13

Which vitamin is most likely to be destroyed by exposure to light, and what is a classic symptom of its deficiency?

Accepted Answer

Riboflavin (Vitamin B2); Cracking of lips and corners of mouth

Question 14

Which of the following is a function of choline in the body?

Accepted Answer

Synthesis of the neurotransmitter acetylcholine

Question 15

A patient with a history of alcoholism presents with mental confusion, psychosis, and memory disturbances. Which vitamin deficiency is most likely, and what is the syndrome called?

Accepted Answer

Thiamin (Vitamin B1); Wernicke-Korsakoff syndrome

Question 16

Which of the following factors does NOT significantly affect the bioavailability of vitamins?

Accepted Answer

The color of the food

Question 17

Which vitamin is involved in the regeneration of the active antioxidant form of vitamin E and enhances iron absorption?

Accepted Answer

Vitamin C

Question 18

Which of the following is a potential risk of excessive folic acid intake from supplements or fortified foods?

Accepted Answer

It can mask vitamin B12 deficiency symptoms.

Question 19

Which vitamin is a coenzyme in glucose metabolism, synthesis of fatty acids and cholesterol, and can be synthesized from tryptophan?

Accepted Answer

Niacin (Vitamin B3)

Question 20

A patient presents with poor growth, skin lesions, decreased immunity, anemia, and neurological symptoms such as anxiety and nightmares. Which vitamin deficiency is most likely?

Accepted Answer

Vitamin B6 (pyridoxine)

Water-Soluble Vitamins: Structure, Function, and Dietary Sources

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