Vitamin/mineral functions and deficiencies Practice Questions

Question 1

You are counseling a pregnant woman who plans to breast-feed exclusively regarding her newborn's nutritional requirements. The child was born at home and the mother only plans for her newborn to receive vaccinations but no other routine medical care. Which vitamins should be given to the newborn?

Accepted Answer

Vitamin K and Vitamin D

Answer

Vitamin B6

Answer

Vitamin K

Answer

Folic acid

Answer

Vitamin D

Question 2

A 29-year-old woman came to the emergency department due to severe symptoms of intoxication and unexplained convulsions. She is accompanied by her husband who reports that she takes disulfiram. There is no prior personal and family history of epilepsy. She shows signs of confusion, hyperirritability, and disorientation. On further evaluation, the patient is noted to have stomatitis, glossitis, and cheilosis. A chest X-ray is unremarkable. The deficiency of which of the vitamins below is likely to be the major cause of this patient’s symptoms?

Accepted Answer

B6

Answer

B12

Answer

B9

Answer

B2

Answer

B3

Question 3

A 61-year-old woman presents for a routine health visit. She complains of generalized fatigue and lethargy on most days of the week for the past 4 months. She has no significant past medical history and is not taking any medications. She denies any history of smoking or recreational drug use but states that she drinks "socially" approx. 6 nights a week. She says she also enjoys a "nightcap," which is 1–2 glasses of wine before bed every night. The patient is afebrile, and her vital signs are within normal limits. On physical examination, there is significant pallor of the mucous membranes. Laboratory findings are significant for a mean corpuscular volume (MCV) of 72 fL, leukocyte count of 4,800/mL, hemoglobin of 11.0 g/dL, and platelet count of 611,000/mL. Stool guaiac test is negative. She is started on oral ferrous sulfate supplements. On follow-up, her laboratory parameters show no interval change in her MCV or platelet level, and she reports good compliance with the medication. Which of the following is the best next step in the management of this patient?

Accepted Answer

Administer iron intravenously

Answer

Transfuse the patient with whole blood

Answer

Administer folate

Answer

Continue oral ferrous sulfate and supplement with omeprazole

Answer

Continue oral ferrous sulfate and supplement with ascorbic acid

Question 4

A 27-year-old female presents to general medical clinic for a routine checkup. She has a genetic disease marked by a mutation in a chloride transporter. She has a history of chronic bronchitis. She has a brother with a similar history of infections as well as infertility. Which of the following is most likely true regarding a potential vitamin deficiency complication secondary to this patient's chronic illness?

Accepted Answer

It may manifest itself as a prolonged PT

Answer

It may result in connective tissue defects

Answer

It may result in corneal vascularization

Answer

It may result in the triad of confusion, ophthalmoplegia, and ataxia

Answer

It may be exacerbated by excessive ingestion of raw eggs

Question 5

A 25-year-old woman presents her physician with a complaint of feeling tired and low on energy for the past 6 months. She also has noticed she has been having trouble performing daily tasks and at times experiencing near-fainting spells. She has no recollection of similar instances in the past. Her past medical history is insignificant, except for the fact that she has been a strict vegan for the last 5 years. Her vital signs are stable. On physical examination, she is visibly pale and has decreased position and vibratory sensation in her both lower extremities. There is decreased lower limb reflexes with sensation intact. A complete blood count - done last week, - shows hemoglobin of 9.7 g/dL with an MCV of 110 fL. The serum levels of which of the following will most likely aid in the physician’s treatment plan?

Accepted Answer

Methylmalonic acid

Answer

Folate

Answer

Homocysteine

Answer

Succinyl CoA

Answer

Ferritin

Question 6

A 10-year-old boy is brought into your clinic by his mother for sunburns that have not been healing. The mother states that he easily gets sunburned. The mother admits she gave birth to him at home and has never taken him to see a doctor. The patient walks with a wide stance gait and appears unstable on his feet. He has an extensive erythematous, scaling, hyperkeratotic rash on his face, neck, arms and legs. After extensive workup, the patient is found to have a genetic disorder that results in defective absorption of an important vitamin. Which of the following is likely to be low if measured?

Accepted Answer

Niacin

Answer

Vitamin K

Answer

Folate

Answer

Vitamin A

Answer

Vitamin B12

Question 7

A 4-year-old boy is brought to the physician because of a rash and difficulty swallowing. His family emigrated from Nigeria 2 months ago. Examination shows an erythematous rash with fine yellow scales on his eyebrows and nasolabial folds. Oral examination shows an erythematous throat and swollen tongue. There is peeling and fissures of the skin at the corners of the mouth and cracking of the lips. His hemoglobin concentration is 9.6 g/dL; mean corpuscular volume is 89 μm3. Erythrocyte glutathione reductase assay shows an increased activity coefficient. This patient is most likely deficient in a vitamin that is a precursor to which of the following molecules?

Accepted Answer

Flavin adenine dinucleotide

Answer

Nicotinamide adenine dinucleotide

Answer

Thiamine pyrophosphate

Answer

Methylcobalamin

Answer

Pyridoxal phosphate

Question 8

A 19-year-old woman with a known history of malabsorption presents with a painful red tongue, red eyes, and cracked lips. She says her symptoms gradually began 4 months ago after moving away from home for college. She also complains of photophobia, spontaneous lacrimation, and itchy dermatitis. Past medical history is significant for a long-standing malabsorption syndrome, which she says that she hasn't been able to maintain her normal diet or take her vitamins regularly due to her busy schedule. The patient is afebrile and vital signs are within normal limits. On physical examination, she has a malnourished appearance with significant pallor. Conjunctival injection is present bilaterally. Which of the following diagnostic tests will be most helpful to support the diagnosis of the most likely vitamin deficiency in this patient?

Accepted Answer

Measurement of erythrocyte glutathione reductase activity

Answer

Measurement of erythrocyte folate levels

Answer

Measurement of erythrocyte glutamic oxaloacetic transaminase activity

Answer

Measurement of erythrocyte transketolase activity

Answer

Measurement of serum methylmalonic acid levels

Question 9

A 5-year-old boy is brought to the physician’s office with complaints of being tired constantly, which has limited his ability to walk or play with his friends. Physical examination in the physician’s office is normal. Further testing reveals that the patient has a genetic mutation in an enzyme and muscle biopsy shows high levels of alpha-ketoglutarate and low levels of succinyl-CoA as compared to normal. The enzyme that is most likely deficient in this patient requires which of the following as a cofactor?

Accepted Answer

Vitamin B1

Answer

Vitamin B6

Answer

NADH

Answer

Carbon dioxide

Answer

ATP

Question 10

A 40-year-old male with Down syndrome is brought to your clinic by his mother. She reports that over the past few months he has started having difficulty managing his daily routine at his assisted-living facility and no longer seems like himself. She says that last week he wandered away from the facility and was brought back by police. Additionally, he has stopped taking his regular antiepileptic medication, and she is concerned that he might have a seizure. TSH is checked and is normal. Which of the following is most likely to be responsible for this man's current presentation?

Accepted Answer

Abnormal protein metabolism

Answer

Premature degradation of a protein

Answer

Hormone deficiency

Answer

Nutritional deficiency

Answer

Expansion of trinucleotide repeats

Vitamin/mineral functions and deficiencies

Study Resources

Lessons

Questions

Flashcards

Lessons

Fat-soluble vitamins (A, D, E, K)

Water-soluble vitamins - B complex

Vitamin C (ascorbic acid)

Macrominerals (Na, K, Ca, Mg, P, Cl)

Trace minerals (Fe, Zn, Cu, Se, I)

Vitamin cofactor functions in metabolism

Deficiency syndromes of fat-soluble vitamins

Deficiency syndromes of water-soluble vitamins

Mineral deficiency disorders

Vitamin toxicity syndromes

Dietary sources and requirements

Assessment of vitamin/mineral status

Practice Questions

Flashcards

About Vitamin/mineral functions and deficiencies for USMLE

Lessons in Vitamin/mineral functions and deficiencies

Master Vitamin/mineral functions and deficiencies