Water-soluble vitamin deficiency and toxicity Quiz: Ace Your Exams

A 54-year-old man comes to the clinic with chronic fatigue and dyspnea on exertion over the last 2 months. He also reports 2 episodes of diarrhea and abdominal bloating. A week ago, he had a syncopal episode that was preceded by palpitations and lightheadedness while he was on a family vacation. He has had no chest pain, fevers, or cough. Past medical history is significant for hyperlipidemia managed with atorvastatin. His elder brother died of cirrhosis at the age of 50. The patient does not use tobacco, alcohol or illicit drugs. The patient started taking multiple high-dose vitamins daily in an effort to become “healthier.” He returned from a business trip to Brazil 2 months ago. Temperature is 37.0 C (98.6°F), blood pressure is 118/70 mmHg, and pulse is 90/min. On examination, his skin appears hyperpigmented. Hepatomegaly is noted on abdominal examination. Cardiac examination is normal. EKG shows sinus rhythm, and an echocardiogram reveals abnormal diastolic relaxation of the left ventricle with an ejection fraction of 50% and no wall motion abnormalities. Laboratory results are as follows:

 

Laboratory value	Result
Serum chemistries
Hemoglobin	14  g/dL
Platelet count	200,000/mm3
Leukocytes	6,500/mm3
Blood urea nitrogen	14 mg/dL
Creatinine	0.8 mg/dL
Fasting glucose	145 mg/dL
AST	120 U/L
ALT	98 U/L
Ferritin	1700 µg/L

Which of the following could be associated with this patient’s current clinical manifestations?