Question 1

Which of the following statements best explains why fat-soluble vitamins are more likely to cause toxicity than water-soluble vitamins?

Accepted Answer

Fat-soluble vitamins are stored in the liver and adipose tissue, so excess intake can accumulate over time.

Question 2

A patient presents with night blindness and frequent respiratory infections. Which vitamin deficiency is most likely responsible, and what is a key food source to recommend?

Accepted Answer

Vitamin A deficiency; recommend liver or orange vegetables like carrots.

Question 3

Which of the following best describes the role of antioxidants in the body?

Accepted Answer

They neutralize free radicals by donating electrons, reducing oxidative damage to cells.

Question 4

A person following a vegan diet is at increased risk for which vitamin deficiency, and what is the physiological reason?

Accepted Answer

Vitamin B12 deficiency; B12 is primarily found in animal products and requires intrinsic factor for absorption.

Question 5

Which of the following factors would most likely decrease the bioavailability of calcium from a meal?

Accepted Answer

High levels of oxalates in the meal, such as from spinach.

Question 6

A patient is diagnosed with macrocytic anemia. Which two nutrients are most likely deficient, and what is a distinguishing laboratory finding?

Accepted Answer

Folate and vitamin B12; laboratory finding: elevated mean corpuscular volume (MCV).

Question 7

Which of the following statements about the regulation of dietary supplements in the United States is correct?

Accepted Answer

Supplements are regulated as foods, not drugs, and do not require FDA approval for safety or efficacy before marketing.

Question 8

A patient with a history of alcoholism presents with confusion, ataxia, and eye movement abnormalities. Which vitamin deficiency is most likely, and what is the syndrome called?

Accepted Answer

Thiamin (vitamin B1) deficiency; Wernicke-Korsakoff syndrome.

Question 9

Which of the following minerals is emphasized in the DASH diet for its role in lowering blood pressure, and what is a major food source?

Accepted Answer

Potassium; major source: fruits and vegetables.

Question 10

A patient consumes large amounts of raw egg whites daily and develops symptoms of hair loss and dermatitis. Which vitamin deficiency is most likely, and what compound in egg whites is responsible?

Accepted Answer

Biotin deficiency; avidin in egg whites binds biotin and reduces its bioavailability.

Question 11

Which of the following best explains why iron absorption is higher from animal sources than from plant sources?

Accepted Answer

Animal sources provide heme iron, which is more efficiently absorbed than nonheme iron from plants.

Question 12

A patient presents with muscle weakness, irregular heartbeat, and is found to have low serum potassium. Which of the following is a likely cause?

Accepted Answer

Use of diuretic medications leading to increased urinary potassium loss.

Question 13

Which vitamin is synthesized in the skin upon exposure to sunlight, and what is its primary function in calcium homeostasis?

Accepted Answer

Vitamin D; it increases intestinal absorption of calcium.

Question 14

Which of the following equations correctly represents the calculation for Body Mass Index (BMI)?

Accepted Answer

$$\mathrm{BMI} = \frac{\mathrm{weight\ (kg)}}{\mathrm{height\ (m)}^2}$$

Question 15

A patient is diagnosed with goiter. Which mineral deficiency is most likely, and what dietary factor can interfere with its absorption?

Accepted Answer

Iodine deficiency; goitrogens in certain vegetables can inhibit iodine uptake.

Question 16

Which of the following is a key function of folate in the body, and how does it relate to homocysteine levels?

Accepted Answer

Folate is required for DNA synthesis and helps convert homocysteine to methionine, lowering homocysteine levels.

Question 17

Which of the following statements about the relationship between vitamin C and the common cold is supported by current evidence?

Accepted Answer

Vitamin C supplements do not prevent the common cold in the general population but may slightly reduce duration or severity.

Question 18

A patient with a genetic disorder has copper accumulation in the liver and brain, leading to neurological symptoms. What is the most likely diagnosis?

Accepted Answer

Wilson's disease

Question 19

Which of the following minerals is a major component of bone and teeth, and what is a key factor that enhances its absorption?

Accepted Answer

Calcium; absorption is enhanced by vitamin D.

Question 20

A patient presents with fatigue, pale skin, and low hemoglobin. Laboratory tests reveal microcytic, hypochromic red blood cells. Which nutrient deficiency is most likely?

Accepted Answer

Iron deficiency

Micronutrients: Fat-Soluble Vitamins, Water-Soluble Vitamins, Major and Trace Minerals

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