The nurse is assessing a patient who is malnourished and has a history of poor nutrition. The patient reports difficulty seeing at night. This patient is likely to be deficient in which fat-soluble vitamin?

A. B complex: The B vitamins are water-soluble and play roles in energy metabolism, nerve function, and red blood cell production. They are not directly linked to vision or night blindness. B. A (retinol): Vitamin A is essential for the production of rhodopsin, a pigment in the retina that allows for vision in low-light conditions. Deficiency leads to night blindness and, if prolonged, can cause more severe eye damage such as xerophthalmia. C. D: Vitamin D is important for calcium absorption and bone health. Deficiency results in rickets in children and osteomalacia in adults, but it does not cause difficulty with night vision. D. K: Vitamin K plays a crucial role in blood clotting and bone health. Its deficiency leads to impaired coagulation and increased bleeding risk, not visual disturbances or night blindness.