Final answer:
The patient likely has a deficiency of vitamin B12, which can cause angular cheilitis, glossitis, stomatitis, seborrheic dermatitis, and normocytic anemia.
Step-by-step explanation:
The patient described with angular cheilitis, glossitis, stomatitis, and normocytic anemia, seborrheic dermatitis is likely to have a deficiency of vitamin B12.
Vitamin B12 deficiency can lead to various symptoms, such as anemia, glossitis (inflammation of the tongue), and skin problems like seborrheic dermatitis. It can also cause angular cheilitis, which manifests as cracks or sores at the corners of the mouth. This deficiency can be caused by poor absorption of vitamin B12, as seen in conditions like pernicious anemia or certain intestinal disorders.