Vitamin C — Functions and Deficiency

A 38-year-old woman with a history of chronic alcoholism and poor oral intake is admitted with complaints of fatigue, bone pain, and spontaneous bruising over her arms and legs. On examination, she has perifollicular hemorrhages, corkscrew hairs, and swollen, bleeding gums with some teeth already lost. Her serum albumin is 2.8 g/dL and hemoglobin is 8.5 g/dL. X-rays of the long bones show a characteristic 'scorbutic rosary' appearance. Which of the following biochemical consequences of her deficiency state directly explains the defective bone matrix formation observed on imaging?

A 42-year-old male construction worker from rural Maharashtra presents with a 3-month history of progressive weakness, joint pain, and bleeding gums. On examination, he has petechial rashes over the lower extremities, swollen and bleeding gums with loose teeth, and poor wound healing over a recent laceration on his forearm. His diet consists mainly of rice, lentils, and occasional vegetables. Hemoglobin is 9.2 g/dL. What is the most likely biochemical defect underlying his clinical presentation?

Vitamin C (ascorbic acid) functions as a cofactor for which of the following enzyme classes?