5. 5)  Sam is in his second year of college enjoying his freedom from his nagging mom. Since he has been living on his own, he eats anything he wants to. He rarely eats any vegetables. He has bacon & eggs for breakfast almost every day and never eats cereal. He won’t drink milk or eat yogurt. He stops by the student cafeteria for grilled chicken fingers, chicken wings, or a hamburger without bread for most meals, and tries to avoid foods containing wheat. He has recently developed a purplish-red tongue that seems to be cracking at the center and the corners of his mouth are dry and cracked. The insides of his cheeks feel swollen and his lips are dry and scaly. What vitamin/mineral is he deficient in?