Abhimelech, a 58-year-old male, comes to the clinic reporting headaches, dizziness, and pruritus, particularly after warm baths. Upon examination, he appears plethoric, with a ruddy complexion. His medical history includes hypertension, managed with medication, but no other significant conditions. Laboratory tests reveal an elevated hemoglobin level of 18.5 g/dL, hematocrit of 57%, and red blood cell count of 6.2 million per microliter, leading to a suspicion of polycythemia. Further tests confirm low erythropoietin levels, normal oxygen saturation, and the presence of the JAK2 V617F mutation, which is pathognomonic for polycythemia vera (PV). Of the following, which vitamin levels are strikingly elevated in patients with polycythemia vera?
