Which symptom can indicate a deficiency in Vitamin B12?

Vitamin B12 deficiency can manifest in several ways, and one of the classic symptoms is glossitis, which is characterized by an inflamed and smooth tongue. This condition occurs due to the essential role that vitamin B12 plays in DNA synthesis and red blood cell formation, which includes the cells involved in maintaining the epithelial tissue of the tongue. Individuals with glossitis may experience pain, swelling, and changes in the appearance of the tongue, which can be significant in diagnosing Vitamin B12 deficiency.

Fatigue is also a common symptom of Vitamin B12 deficiency, typically resulting from anemia, but glossitis specifically serves as a direct indicator affecting the mucosal tissues. Therefore, while fatigue is an important symptom, glossitis provides a more specific and observable sign of the deficiency. In addition, joint pain and insomnia are not directly linked with Vitamin B12 deficiency, making glossitis the most relevant symptom in this context.