Fatigue, brain fog, tingling feet? Doctor warns it could be this Vitamin deficiency

Vitamin B12 deficiency is often called a “silent” condition, quietly affecting the body long before obvious signs appear. Many people assume anemia is the first symptom, but neurological and subtle systemic clues usually appear first, and these are frequently overlooked. Dr Shraddhey Katiyar emphasizes that early recognition is crucial, as untreated deficiency can lead to serious complications. Understanding the hidden signs can prevent irreversible nerve damage and improve overall wellbeing, especially in high-risk individuals who may unknowingly carry this deficiency.

Unexplained fatigue

B12 deficiency initially affects cellular energy, often causing unexplained fatigue even when hemoglobin levels appear normal. Early neurological involvement can present as tingling or numbness in the feet, commonly mistaken for diabetic neuropathy.

Brain fog

Glossitis may appear as a burning sensation or smooth, shiny tongue due to loss of papillae. Brain fog, poor concentration, and mood disturbances such as irritability or low mood are often misattributed to stress or burnout, masking the underlying deficiency.

Imbalance

Patients may also report imbalance or unsteady walking due to posterior column involvement affecting proprioception, increasing fall risk.

Mouth ulcers

Other subtle systemic clues include recurrent mouth ulcers, which arise from impaired mucosal regeneration, and palpitations that occur even before anemia is evident, linked to reduced oxygen delivery at the tissue level.

Vision changes

Vision changes, such as blurred vision or eye strain, can occur if the optic nerve is affected, while subtle hyperpigmentation, especially darkening of the knuckles, is more commonly observed in Indian patients. Recognizing the clinical pattern—neuropathy combined with fatigue or neurological symptoms without anemia—can prompt early testing and intervention.

High-risk groups should remain particularly vigilant. Strict vegetarians, elderly individuals, chronic PPI users, and those with gut disorders such as inflammatory bowel disease or post-surgical changes are especially susceptible.

Dr Katiyar stresses that vitamin B12 deficiency is primarily a neurological disorder, with hematological manifestations appearing later. Waiting for anemia to appear delays treatment, increasing the likelihood of permanent nerve damage. Early recognition, testing, and supplementation can protect neurological function and improve quality of life, highlighting the importance of clinical awareness.