Which symptom is most indicative of vitamin B12 deficiency in post-gastrectomy patients?

In post-gastrectomy patients, the most indicative symptom of vitamin B12 deficiency is peripheral neuropathy. This occurs due to the critical role that vitamin B12 plays in the health of the nervous system and the formation of myelin, the protective sheath around nerves.

In cases of vitamin B12 deficiency, neurological symptoms such as numbness, tingling, or burning sensations in the hands and feet can develop, reflecting the impact of the deficiency on the peripheral nervous system. These symptoms arise because the absorption of vitamin B12 is significantly impaired following gastrectomy, which can lead to more pronounced neurological effects compared to other symptoms.

While fatigue, anemia, and muscle weakness are associated with vitamin B12 deficiency as well, they are often more generalized and can be linked to a variety of other conditions. Fatigue can arise from multiple factors, anemia can occur due to various nutritional deficiencies, and muscle weakness can be seen in many different health scenarios. Thus, peripheral neuropathy stands out as a more specific and direct indication of B12 deficiency, especially following surgical alterations of the gastrointestinal tract.