A recent case shared by Dr. Sudhir Kumar, a senior doctor at Apollo Hospital, highlights the subtle yet significant signs of vitamin B12 deficiency. A 69-year-old man presented with a gradual darkening of the skin on his hands over two months, accompanied by mild tingling sensations in his hands and feet. His vegetarian diet for the past 20 years raised concerns about potential nutritional deficiencies. Laboratory tests revealed a haemoglobin level of 11.1, indicating mild anemia, and a vitamin B12 level of 132 pg/mL, well below the normal range. The presence of hypersegmented neutrophils further confirmed the deficiency. After initiating treatment with vitamin B12 supplementation, the patient showed marked improvement over three months. This case underscores the importance of recognizing early symptoms of nutritional deficiencies, particularly in individuals with restricted diets.