Deck 8: Vitamins and Minerals

Question 1

You are tending to a patient in the emergency room (ER) who presents with the following symptoms: nystagmus, organic toxic psychosis, and ataxia. You notice that the patient is dirty and appears not to have bathed in several days or weeks. There is an odor of vomit and alcohol on his clothing. Given the outward appearance and observed symptoms, your diagnosis is indicative of a deficiency in which of the following vitamins?

A) biotin
B) folate
C) pantothenate
D) riboflavin
E) thiamin

Answer 1

thiamin

Question 2

Wernicke encephalopathy results from a deficiency of vitamin B₁. Which of the following represents classical symptoms associated with this disorder?

A) megaloblastic anemia
B) nausea, peripheral neuropathy, mental depression, ophthalmoplegia
C) numbness, tingling, weakness, sore smooth tongue, anorexia, diarrhea, pallor of the skin and mucous membranes
D) seizure disorders
E) weight loss, diarrhea, dementia, and dermatitis

Answer 2

B
EXPLANATION: Wernicke encephalopathy is most commonly found in chronic alcoholics due to their poor dietetic lifestyles. Wernicke encephalopathy is a syndrome characterized by ataxia, ophthalmoplegia, nystagmus, and confusion. If the disorder is left untreated, it will progress to Wernicke-Korsakoff syndrome which includes impairment of short-term memory, psychosis, coma, and eventually death.

Question 3

A 60-year-old chronic smoker and alcoholic man
Suffering from odynophagia, insomnia, epigastric
Discomfort, and recurrent diarrhea presented to
The outpatient department. Clinical examination
Revealed memory disorientation, stomatitis, glossitis, esophagitis, and exfoliative dermatitis with some
Vesicles on erythematous bases on photoexposed
Sites such as his hands shown in the attached image.
These signs and symptoms are most likely the result
Of a deficiency in which of the following vitamins?

A) biotin
B) cobalamin
C) niacin
D) riboflavin
E) thiamin

Answer 3

niacin

Question 4

Deficiency in which of the following vitamins is associated with progressive keratinization of the cornea?

A) A
B) C
C) D
D) E
E) K

Question 5

The attached radiograph shows the typical bowed legs of an infant suffering from a deficiency in which of the following vitamins?

A) A
B) C
C) D
D) E
E) K

Question 6

Although α-lipoic acid is not truly a vitamin, it is an essential cofactor for several important enzymes. An inability to maintain adequate levels of this lipid-derived molecule would result in which of the following consequences?

A) decreased insulin sensitivity
B) decreased production of reactive oxygen species, ROS
C) increased energy generation from
Carbohydrates
D) increased hepatic production of triglycerides
E) loss of the ability to clot blood

Question 7

Which of the following is associated with increased glucose uptake due to its ability to prevent phosphorylation of downstream effectors of the insulin-signaling cascade?

A) α-lipoic acid
B) vitamin A
C) vitamin D
D) vitamin E
E) vitamin K

Question 8

A deficiency in which of the following vitamins would most likely be associated with prolonged clotting times, hemorrhaging, and anemia?

A) α-lipoic acid
B) C
C) D
D) E
E) K

Question 9

A 45-year-old man, a known alcoholic for at least the past 10 years, reported to a physician for consultation. He complained of burning of eyes, a sore tongue, reduced appetite, and mild abdominal discomfort. Physical examination revealed cracks on the lips and in the corners of the mouth; a red, fissured, and inflamed tongue; dull hair, oily skin, and split nails. A deficiency in which of the following vitamins would best explain the observed symptoms?

A) ...
B) ....
C) .....
D) ......

Question 10

Not all water-soluble vitamins are strictly required in the diet since the human body has the capacity to synthesize at least one of this class of vitamin. However, the ability to do so is limiting and not of sufficient capacity to provide all the necessary coenzyme required for normal metabolic processes. Which of the following is this vitamin?

A) α-lipoic acid
B) folate
C) niacin
D) riboflavin
E) thiamin

Question 11

A 58-year-old male stumbles into a local soup kitchen mumbling about aliens and space craft. He is dirty, unshaven, wearing tattered clothing, and reeking of alcohol. He is discovered to have died in the alleyway during the night. At autopsy, a sagittal section through the brain shows severe pigmentation of the mammillary bodies due to apparent hemorrhage. A deficiency in which of the following vitamins would be expected to cause hemorrhaging in this brain structure?

A) biotin
B) folate
C) pyridoxamine
D) riboflavin
E) thiamin

Question 12

A smear of your patients' blood is shown in the following picture demonstrating that the person suffers from a form of anemia. A deficiency in which of the following vitamins would lead to the anemia shown in the slide?

A) B₁ (thiamin)
B) B₆ (pyridoxal phosphate)
C) B₁₂ (cobalamin)
D) biotin
E) K

Question 13

A patient presents with pale skin, sunken eyes, sore gums, muscle pain, loose teeth, and corkscrew-shaped hair. A deficiency in which of the following vitamins would result in the observed symptoms?

A) ascorbic acid
B) biotin
C) pyridoxal
D) riboflavin
E) thiamin

Question 14

The vitamin involved in biochemical reactions concerned with the transfer of methyl, methylene, or formyl groups is a derivative of which of the following vitamins?

A) α-lipoic acid
B) biotin
C) folic acid
D) pyridoxine
E) riboflavin

Question 15

Wernicke encephalopathy syndrome is caused by a deficiency of which of the following?

A) biotin
B) cobalamin
C) pyridoxal phosphate
D) riboflavin
E) thiamine

Question 16

Scurvy is due to a dietary deficiency of which vitamin?

A) A
B) B₆ (pyridoxal phosphate)
C) B₁₂ (cobalamin)
D) C
E) D

Question 17

A deficiency of vitamin B12 in humans results in anemia primarily because it is which of the following?

A) a cofactor in the biosynthesis of purine nucleotides required for the synthesis of DNA
B) involved in the conversion of N⁵-methyl-THF to THF
C) necessary for the absorption of folic acid from the gut
D) required for the conversion of cystathionine to cysteine
E) utilized as a cofactor in synthesis of thymidine nucleotides

Question 18

Which of the following represents a significant biochemical role of vitamin C?

A) blood coagulation
B) calcium homeostasis
C) connective tissue production
D) metabolic functions of copper
E) steroid hydroxylation

Question 19

When vitamin D is deficient, what 2 disorders occur most readily?

A) kidney failure and bent bones
B) megaloblastic anemia and Wernicke-Korsakoff syndrome
C) osteoporosis and diverticulosis
D) osteomalacia and xerophthalmia
E) rickets and osteomalacia

Question 20

The ability of rod cells in the eye to respond to light and transmit that response to the optic nerve requires that the 11-cis form of vitamin A be attached to which of the following proteins?

A) cGMP phosphodiesterase
B) Na+ channel
C) rhodopsin
D) scotopsin
E) transducing

Question 21

Vitamin K serves as a coenzyme in reactions that result in the modified activity of several enzymes of the blood coagulation cascade. Which of the following amino acid modifications requires the activity of vitamin K?

A) aspartate to β-carboxyaspartate
B) glutamate to g-carboxyglutamate
C) lysine to hydroxylysine
D) lysine to β-methyllysine
E) proline to hydroxyproline

Question 22

The inability to rapidly synthesize DNA during the process of erythrocyte maturation leads to abnormally enlarged erythrocytes. This disorder is referred to as macrocytic anemia and is caused by a deficiency in which of the following vitamins?

A) ascorbate
B) biotin
C) folate
D) niacin
E) thiamine

Question 23

When fatty acids with odd numbers of carbon atoms are oxidized in the β-oxidation pathway, the final product is 1 mole of acetyl-CoA and 1 mole of the 3-carbon molecule, propionyl-CoA. In order to use the propionyl carbons, the molecule is carboxylated, converted ultimately to succinyl-CoA, and fed into the TCA cycle. Which of the following represents the vitamin cofactor required in one of the steps of this conversion?

A) cobalamin (B₁₂)
B) pantothenic acid (B₅)
C) pyridoxine (B₆)
D) riboflavin (B₂)
E) thiamine (B₁)

Question 24

The terminal ileum was removed from a
50-year-old woman during excision of a tumor. About 3 years later, the patient was admitted to the hospital. She is very pale. Hemoglobin is 9 g/dL, MCV (mean corpuscular volume) has increased to 110 mm3 (110 fL). The provisional diagnosis is a vitamin deficiency. Which of the following vitamins is the most likely one causing the symptoms?

A) A
B) B₁
C) B₆
D) B₁₂
E) K

Question 25

A patient is found to be deficient in folate. This patient is anemic, and a complete blood count indicates that the MCV is 105 fL (normal range: 80-96) and the mean corpuscular hemoglobin concentration (MCHC) is 34 g/dL (normal range: 32-36). The anemia is thus macrocytic and normochromic. In this patient, how would you predict that the MCH (mean corpuscular hemoglobin) would compare to the normal range?

A) MCH would be elevated with respect to the normal range
B) MCH would be depressed with respect to the normal range
C) MCH would be within the normal range
D) this cannot be determined based on the information provided

Question 26

The patient is a 43-year-old man. He is anemic, with a hemoglobin level of 12.2 g/dL (normal is 15.5 g/dL). The erythrocytes are microcytic
(MCV = 70 fL, with normal MCV = 80-100 fL). Which of the following would most likely be present in this patient?

A) acute bleeding
B) folate deficiency
C) iron deficiency
D) vitamin B₁₂ deficiency
E) vitamin K deficiency

Question 27

A 14-month-old baby boy is brought to your office by his mother because he seems to be in pain whenever he tries to move. During your physical examination you note bowing of his legs, depression of the sternum with outward projection of the ends of the ribs, reluctance to move his limbs, and numerous bruises on his legs as well as gingival hemorrhages. These findings lead you to suspect that this child suffers from a dietary deficiency of which of the following vitamins?

A) A
B) B₁ (thiamine)
C) B₁₂ (cyanocobalamin)
D) C (ascorbate)
E) D (calciferol)

Question 28

As the ER physician you are tending to a 59-year-old female patient who has a broken left fibula. Upon physical exam you discover she also has multiple bruises on her arms, legs, and upper torso. She also complains of painful gums and significant bleeding whenever she brushes her teeth. She reports that she subsists on bouillon soup, tea, plain pasta, and dinner rolls. Blood work indicates that she is mildly anemic with microcytic erythrocytes. Given these signs and symptoms, this patient most likely is suffering from the effects of a deficiency in the activity of which of the following enzymes?

A) branched-chain ketoacid dehydrogenase
B) lysyl hydroxylase
C) methionine synthase
D) pyruvate dehydrogenase
E) transketolase

Question 29

A 29-year-old female has just become pregnant and is at the doctor's office for her first pre-natal exam. This is the first time this patient has been seen by the ob-gyn. In reviewing the patients medical records the physician discovers that the woman takes Dilantin (phenytoin) to mcontrol her epileptic seizures. The physician recommends that the woman stop the Dilantin and switch to Carbatrol (carbamazepine). If the woman refuses to comply with the change in seizure medication which of the following is most likely to be defective in her newborn resulting in potentially fatal bleeding episodes?

A) g-carboxylation of glutamate
B) hydroxylation of lysine
C) methylation of homocysteine
D) oxidation of lysine
E) synthesis of heme

Question 30

A 23-year-old man has been consuming large quantities of raw egg whites as part of his current body-building routine. He has developed a rash and severe muscle pain. Blood work indicates he has anemia. His diet prevents intestinal absorption of a vitamin leading to inhibition in the synthesis of which of the following?

A) DNA
B) fatty acid
C) glycogen
D) protein
E) RNA

Question 31

After metabolic conversion in the body, coenzyme forms of folate and vitamin B₁₂ are both involved in methylation of which of the following?

A) homocysteine
B) norepinephrine
C) pyridine
D) serotonin
E) uridylic acid

Question 32

You are the attending physician in the ER. You are examining a 48-year-old man brought by his wife because of a recent change in his mental status. Physical examination shows horizontal and vertical nystagmus, bilateral facial nerve palsy, and truncal ataxia. The most likely explanation for these findings is a deficiency in which of the following vitamins?

A) folate
B) vitamin B₁
C) vitamin B₆
D) vitamin C
E) vitamin D

Question 33

The activity of aspartate aminotransferase (AST) requires which of the following vitamins as a coenzyme?

A) folate
B) vitamin B₁
C) vitamin B₂
D) vitamin B₆
E) vitamin B₁₂

Question 34

As an essential component of the nucleotide analog, FAD, which of the following vitamins plays a major role in the transfer of reducing equivalents?

A) folate
B) vitamin B₁
C) vitamin B₂
D) vitamin B₆
E) vitamin B₁₂

Question 35

The activity of which of the following enzymes in the erythrocyte will be decreased in patients with a deficiency of thiamin?

A) adenosine deaminase
B) aspartate aminotransferase (AST)
C) pyruvate kinase
D) transaldolase
E) transketolase

Question 36

Which of the following laboratory findings is most likely in a 37-year-old woman with a thiamin deficiency?

A) decreased plasma concentration of alanine
B) increased erythrocyte transketolase activity
C) increased leukocyte α-ketoglutarate dehydrogenase activity
D) increased plasma concentration of glucose
E) increased plasma concentrations of pyruvate and lactate

Question 37

You are a physician working in a clinic, who sees many transient workers. You find that almost 30% of the patients you see are deficient in thiamin and their erythrocytes are markedly deficient in transketolase activity. Examination of liver function in these individuals would most likely show deficiency in which of the following metabolic processes?

A) biosynthesis of fatty acids from acetyl-CoA
B) biosynthesis of ketone bodies
C) conversion of glycerol to glucose during fasting
D) conversion of pyruvate to acetyl-CoA
E) incorporation of dietary glucose into hepatic glycogen

Question 38

You are an ER physician examining a 67-year-old
Woman. She was brought to the hospital by her neighbor because he found her passed out in the front yard. History reveals that she lives by herself and consumes a diet which consists primarily of lettuce and rice. She has not consumed any meat products for over 5 years and does not supplement her diet with vitamins. She reports that she is frequently quite tired. Blood work indicates she has severe megaloblastic anemia. Which of the following reaction pathways is most likely impaired in this patient?

A) branched-chain amino acid degradation
B) glucose 6-phosphate being converted to ribulose 5-phosphate and CO2
C) glycolysis
D) heme synthesis
E) thymidine nucleotide biosynthesis

Question 39

You are examining a 27-year-old pregnant woman who is at 32 weeks' gestation. Blood work indicates she is suffering from macrocytic anemia. Her diet consists mainly of starchy foods with little meat and green vegetables. Which of the following vitamins is most likely deficient in this woman?

A) folate
B) vitamin B₁
C) vitamin B₂
D) vitamin B₆
E) vitamin C

Question 40

A strict vegan diet restricts the intake of meat, eggs, milk, cheese, or other animal-derived foods. You are examining your patient who follows this particular dietary regimen. Urine analysis shows increased concentration of methylmalonic acid. This finding is indicative of which of the following?

A) excess methylmalonate in the diet
B) fatty acid deficiency
C) folate deficiency
D) protein deficiency
E) vitamin B₁₂ (cobalamin) deficiency

Question 41

A 45-year-old man is brought to the ER by his wife because he has exhibited confusion for the past few days. The attending physician asks him to follow his pen with his eyes. He notes that on extreme lateral motion his eyes exhibit an involuntary rhythmic movement toward the midline and then back to lateral gaze. The patient is unable to do finger-to-nose or heel-to-shin movements or walk in a straight line by placing the heel of one foot directly in front of the toes of the other foot. Given these signs and symptoms, which of the following vitamin deficiencies is most likely in this patient?

A) folate
B) vitamin B₁
C) vitamin B₂
D) vitamin B₆
E) vitamin B₁₂

Question 42

An individual with pernicious anemia has an inability to metabolize which of the following compounds?

A) acetyl-CoA
B) butyryl-CoA
C) methylmalonyl-CoA
D) palmitoyl-CoA
E) stearoyl-CoA

Question 43

Conversion of propionyl-CoA to succinyl-CoA requires which of the following pairs of vitamins?

A) vitamin B₁ (thiamin) and vitamin B₅ (pantothenate)
B) vitamin B₂ (riboflavin) and vitamin B₃ (niacin)
C) vitamin B₃ (niacin) and folate
D) vitamin B₆ (pyridoxine) and vitamin B₁₂ (cobalamin)
E) vitamin B₁₂ (cobalamin) and biotin

Question 44

Patients with scurvy are most likely to have a defect in which of the following reactions?

A) carboxylation
B) decarboxylation
C) hydroxylation
D) methyl group transfer
E) transamination

Question 45

You are examining a 57-year-old woman, who has complains that her teeth feel loose and that her gums bleed easily when she eats. In taking her history you find that her diet is restricted and includes no fresh citrus fruits or leafy green vegetables. Which of the following vitamins is most likely to be deficient in this patient?

A) A
B) B₁ (thiamin)
C) B₂ (riboflavin)
D) C
E) K

Question 46

As a physician volunteer in a free clinic, you are examining a 52-year-old homeless man. You note that he has numerous petechiae and suspect impaired collagen production. Given his poor dietary habits, you determine that he lacks adequate intake of vitamin C. For which of the following steps of collagen synthesis is ascorbic acid required?

A) cross-linking lysine and hydroxylysine residues
B) glycosylation of hydroxylysine residues
C) hydroxylation of proline residues
D) removal of the signal peptide from preprocollagen
E) translocation of collagen peptides into the endoplasmic reticulum

Question 47

The active hormonal form of vitamin D requires several enzymatic steps. The final step in the synthesis of 1,25-dihydroxycholecalciferol occurs in which of the following tissues?

A) bone
B) intestine
C) kidney
D) liver
E) spleen

Question 48

A 50-year-old woman was diagnosed 2 years ago with primary biliary cirrhosis. Given her diagnosis, she is at greatest risk for becoming deficient in which of the following?

A) B₁ (thiamin)
B) B₁₂ (cobalamin)
C) C
D) E
E) niacin

Question 49

A 10-year-old boy with cystic fibrosis is brought
To the physician because his mother has noticed that it seems to take him significantly longer to stop bleeding when he has a cut. He had been prescribed pancreatic digestive enzyme supplements because his stools were bulky and large as well as malodorous. Being a child he admits that he does not take them regularly. Physical examination shows several bruises on his skin. A deficiency in which of the following nutrients is the most likely explanation for his bleeding disorder?

A) ascorbic acid
B) essential fatty acids
C) folate
D) iron
E) vitamin K

Question 50

A 50-year-old man is being examined by his physician due to complaints of frequent oily bowel movements. He indicates that his stools are also difficult to flush down the toilet. His history indicates chronic pancreatitis and a high level of alcohol consumption. Which of the following laboratory findings is most likely to be increased in this man?

A) erythrocyte count
B) eosinophil count
C) leukocyte count
D) platelet count
E) prothrombin time

Question 51

A dietary deficiency of vitamin C would result in a decrease in which of the following?

A) amount of THF available for one-carbon metabolism
B) conversion of norepinephrine to epinephrine
C) conversion of proline to hydroxyproline
D) production of creatine
E) supply of "active formaldehyde" units

Question 52

Vitamin K is necessary for normal blood coagulation. Which of the following processes of hemostasis is dependent on the activity of this vitamin?

A) it complexes with platelets in the first wave of platelet aggregation
B) it induces the release of von Willebrand factor
C) it inhibits the activation of the fibrinolytic system
D) it initiates the contact phase by activating factor XI (plasma thromboplastin antecedent)
E) it is a required cofactor for the introduction of gla-residues into coagulation factors

Question 53

When increased in the serum, which of the following stimulates the synthesis of 1,25-dihydroxycholecalciferol?

A) calcitonin
B) calcium
C) 25-hydroxycholecalciferol
D) parathyroid hormone
E) phosphate