During regular check-up the doctor examines a young woman, a student, with height of 162 cm and weight of 59 kg. She complains that in the evening she becomes unable to see clearly the objects around her. Objectively her skin is dry, presents with hyperkeratosis. Her daily ration has the following vitamin content: vitamin A – 0.5 mg, vitamin B1 – 2.0 mg, vitamin B2 – 2.5 mg, vitamin B6 – 2 mg, vitamin C – 70 mg. Make the diagnosis: