Nutrition, Vitamins & Metabolic Disorders Practice Questions

A 6-month-old infant is brought to the clinic for a routine check-up. The parents are recent immigrants from a region where iodized salt is not readily available. Physical examination reveals coarse facial features, an umbilical hernia, a large tongue, and generalized hypotonia. The infant's growth and developmental milestones are significantly delayed. Which of the following mineral deficiencies is the most likely cause of this patient's condition?

A 68-year-old man presents to the clinic complaining of fatigue, generalized weakness, and bleeding gums for the past two months. He lives alone and admits to a very poor diet, consisting mainly of toast and canned soup. Physical examination reveals swollen, purplish gums that bleed easily with palpation. He also has multiple perifollicular hemorrhages on his lower extremities. Which of the following vitamin deficiencies is the most likely cause of his symptoms?

A 2-year-old boy is brought to the emergency department after his parents noted his urine turning dark upon standing in his diaper. He is otherwise asymptomatic. Physical examination is unremarkable. Urinalysis shows dark brown-black urine after exposure to air. The patient is diagnosed with alkaptonuria. This condition is caused by a deficiency in which of the following enzymes?