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

A 25-year-old woman comes to the clinic due to myalgia, loss of appetite and a skin rash.  She noticed a progressively worsening skin rash around her eyes, nose and mouth over the course of the last 4 weeks. She has not had a fever, and the rash is not painful or pruritic. Five months ago, she began an intense fitness regimen with a strict diet, which includes eating multiple egg whites everyday, as well as a protein shake every morning, in which she puts several raw eggs. Temperature is 37.0°C (98.6°F), pulse is 80/min, respirations are 20/min, and blood pressure is 125/85 mmHg. BMI is 19 kg/m2. Physical examination reveals macular patches around her eyes, nose and mouth. The physician suspects a nutritional deficiency. The cause of this patient’s symptoms is determined to be a vitamin deficiency that acts as a cofactor for the enzyme acetyl-CoA carboxylase. Which of the following additional biochemical processes uses the deficient vitamin as a cofactor?