What are the symptoms of vitamin b12 deficiency?
B12 deficiency develops quietly over several years as liver stores are gradually depleted.
- Pins-and-needles sensation, tingling, or burning in the feet or toes
- Numbness in hands or feet, feeling like wearing socks or gloves
- Chronic fatigue, unrefreshing sleep, and lack of energy
- Difficulty maintaining balance or unsteady walking in the dark
- Forgetfulness, brain fog, and mood changes
- Sore, smooth, red tongue (glossitis)
- Pale or slight yellowish skin tone
Warning signs: go to hospital at once
These indicate advanced neurological involvement that may become irreversible if untreated.
- Severe unsteadiness with frequent falls
- Loss of vibration and position sensation in legs
- Severe memory impairment or acute confusion
- Extreme weakness with breathlessness at minimal exertion
- Urinary or bowel incontinence
Call 108 or go to the nearest emergency department.
The 3 phases of vitamin b12 deficiency
Asymptomatic drop
Serum B12 drops below 300 pg/mL. Cell reserves decline with minimal symptoms.
Peripheral neuropathy
B12 below 200 pg/mL. Tingling feet, fatigue, and megaloblastic anemia emerge.
Neurological deficit
Subacute combined degeneration of the spinal cord. Requires urgent high-dose injectable B12.
Which test shows vitamin b12 deficiency?
Evaluated through blood testing in our own clinical laboratory.
| Test | Best time | What it tells you |
|---|---|---|
| Serum Vitamin B12 Level | Next day | Directly measures active B12 in the bloodstream (< 200 pg/mL confirms deficiency) |
| Complete Blood Count (CBC) | Same visit | Identifies large, oversized red blood cells (high MCV > 100 fL) |
| Fasting Blood Sugar & HbA1c | Same visit | Checks if tingling is due to diabetes, B12, or both together |
How is vitamin b12 deficiency treated?
Treatment involves replacing B12 through oral tablets, sublingual supplements, or intramuscular injections depending on the severity of neurological symptoms.
At Nareddy Care
- Comprehensive nerve and reflex examination by Dr. Vishnu Anjan Nareddy
- Diagnostic blood tests processed in our laboratory
- Tailored treatment: therapeutic oral B12 or short injection courses
- Annual monitoring for all patients taking metformin
- Dietary review and practical nutrition coaching
Do at home
- Take prescribed B12 supplements consistently as advised
- Include dairy products (milk, curd, paneer) regularly if vegetarian
- Report any persistent numbness or balance trouble to your physician promptly
- Keep a record of your annual B12 levels alongside your HbA1c
Avoid
- Stopping metformin on your own; B12 is easily replaced while staying on metformin
- Ignoring tingling feet as 'just tiredness' or 'old age'
- Assuming multivitamin syrups provide enough therapeutic B12 to reverse nerve damage
- Delaying treatment until walking balance is affected
How to prevent vitamin b12 deficiency
Routine annual B12 screening for anyone on metformin for over 2 years, regular dairy intake for vegetarians, and timely supplementation.
Questions people ask
Why does metformin cause vitamin B12 deficiency?
Metformin interferes with calcium-dependent absorption of the B12-intrinsic factor complex in the terminal ileum of the gut. An annual blood test catches this early.
Will tingling in my feet go away with B12 treatment?
Yes, when treated early, nerve tingling and numbness significantly improve or resolve completely over several months of adequate supplementation.
Can vegetarians get enough vitamin B12 from food alone?
Plant foods contain virtually zero active vitamin B12. Vegetarians rely on milk, curd, paneer, fortified foods, and periodic oral B12 supplements.
Adults seeDr. Vishnu Anjan NareddyMD (General Medicine)Children seeDr. Bramhini NareddyMD (Paediatrics)