Q. A 54-year-old woman presents to the clinic with a history of chronic fatigue and weakness. She mentions she has had occasional diarrhea and weight loss over the past few months. The patient admits to excessive alcohol consumption and a diet lacking in fresh fruits and vegetables. On examination, she appears pale and mildly jaundiced. The physician notes a smooth, red tongue and angular cheilitis. Blood tests reveal a macrocytic anemia with hypersegmented neutrophils. Given her symptoms and lab findings, the physician is inclined to diagnose her with a deficiency of a specific vitamin. Considering the patient's clinical presentation and laboratory findings, what is the metabolic abnormality that the physician is most likely to notice that would guide the diagnosis toward **folate** deficiency?