Quick Answer
Numbness in feet, memory problems, fatigue — B12 deficiency is common, treatable, and often missed.
Medically reviewed by Dr. Jitendra Prasad Yadav • NMC 8029 • Kathmandu Neurology Clinic & Cognitive Center
Vitamin B12 deficiency is one of the most common yet overlooked causes of neurological symptoms in Nepal. It causes peripheral neuropathy (numbness, tingling, burning in feet and hands), cognitive problems (memory, concentration, "brain fog"), and megaloblastic anemia. Because symptoms develop gradually and overlap with many conditions, B12 deficiency is frequently missed until it has caused significant damage.
Why B12 deficiency is common in Nepal
- Vegetarian and vegan diets: B12 is found almost exclusively in animal products. Strict vegetarians are at high risk without supplementation.
- Metformin use: this common diabetes medication reduces B12 absorption over years.
- Gastrointestinal conditions: celiac disease, Crohn's, atrophic gastritis, and stomach surgery impair absorption.
- Proton pump inhibitors: long-term acid-reducing medications reduce B12 absorption.
- Age: absorption declines after 50; routine monitoring is reasonable.
Neurological symptoms
Peripheral neuropathy
- Tingling, numbness, or burning starting in feet and progressing upward (stocking-glove pattern).
- Loss of vibration and position sense; muscle weakness; ataxia.
Cognitive symptoms
- Memory problems, poor concentration, slow processing.
- In severe cases, dementia-like syndrome that can be reversible with treatment.
Other symptoms
- Fatigue and weakness (anemia); pale or jaundiced skin; sore tongue; depression; vision problems.
Diagnosis
- Serum B12: below 200 pg/mL is deficient; 200-300 pg/mL is borderline.
- Methylmalonic acid (MMA): elevated in functional deficiency even with borderline B12.
- Complete blood count: megaloblastic anemia (large red cells).
B12 is routinely checked at Kathmandu Neurology Clinic in patients with neuropathy, cognitive symptoms, or unexplained anemia.
Treatment and prevention
B12 deficiency is completely treatable with oral supplementation (1000-2000 mcg daily) or intramuscular injections for severe deficiency or malabsorption. Neurological recovery takes months; early detection prevents permanent damage.
- Vegetarians/vegans: supplement 1000 mcg daily.
- Metformin users: annual B12 monitoring.
- Adults over 50: consider routine screening.
If you have numbness, tingling, memory problems, or unexplained fatigue, a simple B12 blood test can identify this treatable cause.
This article is educational and does not replace individual medical advice.
Frequently asked questions
Answers reviewed by Dr. Jitendra Prasad Yadav • MBBS, MD (Internal Medicine), FICN (Neurology), FCNV, FIHM • NMC 8029
Supplements only help when a deficiency is present; underlying cause-directed care is needed.
If the underlying cause is corrected early (e.g., improving glucose control, treating vitamin deficiency), improvement may occur. Long-standing neuropathy is often not fully reversible.
Brief slips without functional impact are often benign; persistent, progressive interference with daily tasks warrants assessment.
Yes, anxiety, depression, and poor sleep frequently impair attention and recall and improve when treated.
More: All FAQs → · Ask Dr. Jitendra →
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References & Review
Reviewed by Dr. Jitendra Prasad Yadav • Last reviewed: 2026-11-10
- International Classification of Headache Disorders, 3rd edition (ICHD-3).
- Harrison's Principles of Internal Medicine — Neurology sections.
- American Academy of Neurology guidelines for selected conditions (where applicable).
Content is educational and aligns with standard medical references; individual evaluation may vary. External links provide context and do not imply endorsement.