Vitamin B12 is important for nerve health. Some patients continue to have tingling, numbness, burning, or balance changes even after blood sugar improves because another factor such as B12 deficiency or poor absorption may be contributing. Patients taking metformin, older adults, and people with absorption issues should discuss B12 testing with their provider.
- B12 deficiency can contribute to neurological symptoms, including tingling and numbness.
- Long-term metformin use is associated with reduced B12 levels in some patients.
- Neuropathy care works best when metabolic, nutritional, circulation, and nerve-signaling factors are all evaluated.
Last updated: April 14, 2026
Reviewed by: Neuropathy Relief Center of Miami team
Many neuropathy patients are told to focus only on blood sugar. Blood sugar matters, but it is not the only factor that affects nerves.
Some patients say:
- “My A1C improved, but my feet still tingle.”
- “My burning is better, but numbness remains.”
- “My hands and feet both feel pins and needles.”
- “I take metformin and wonder if B12 matters.”
- “My labs were called normal, but I still feel neuropathy symptoms.”
At the Neuropathy Relief Center of Miami, we see this in patients across Miami, Fort Lauderdale, Miami-Dade County, Broward County, and the Florida Keys, and in visitors from the USA, Colombia, Chile, Argentina, Mexico, and the Caribbean.
This blog is educational and not a diagnosis. Do not stop medications or start high-dose supplements without discussing your situation with a qualified provider.
Why B12 matters for nerves
Vitamin B12 is involved in nerve function, red blood cell production, and myelin health. Myelin is part of the protective covering around nerves. When B12 is low or poorly utilized, neurological symptoms can appear.
Symptoms associated with B12 deficiency may include:
- tingling
- numbness
- burning
- balance issues
- weakness
- fatigue
- memory or concentration changes
- gait changes
These symptoms can overlap with diabetic neuropathy, which is why evaluation matters.
Why symptoms can persist after blood sugar improves
Improving blood sugar is important, but nerves may still struggle if other drivers remain active.
Possible contributors include:
- B12 deficiency
- poor B12 absorption
- inflammation
- microcirculation problems
- mechanical compression
- medication-related nutrient issues
- sleep disruption
- ongoing metabolic swings
The best plan asks, “What else may be affecting nerve recovery?”
Metformin and B12
Metformin is commonly used for type 2 diabetes and insulin resistance. Some patients on long-term metformin can develop lower B12 levels. This does not mean metformin is bad or should be stopped. It means patients with neuropathy symptoms should discuss B12 monitoring with their provider.
This is especially important if symptoms include:
- tingling in both feet and hands
- worsening numbness despite better glucose control
- balance changes
- fatigue or weakness
- cognitive fog or memory concerns
Who should ask about B12 testing?
Ask your provider about B12 if you:
- take metformin long term
- have neuropathy symptoms
- eat little or no animal products
- have digestive absorption issues
- have had stomach or intestinal surgery
- use acid-reducing medications long term
- are older
- have unexplained anemia or fatigue
Testing may include B12 levels and sometimes additional markers depending on the provider’s judgment.
Why not just supplement blindly?
Some people start supplements without testing. While B12 is generally considered safe for many people, blind supplementation can confuse the clinical picture. It is better to test, document, and follow a plan.
Also, not all neuropathy is caused by B12 deficiency. If symptoms are progressing, you need a broader evaluation rather than assuming one nutrient explains everything.
A practical symptom checklist
Track:
- tingling location: feet only vs hands and feet
- numbness severity
- balance changes
- fatigue level
- diet pattern
- medication history
- blood sugar trends
- sleep quality
- symptom change over time
Bring this to your provider. Patterns help guide testing.
How the Dr. Alfonso Neuropathy Treatment Protocol helps
The Dr. Alfonso Neuropathy Treatment Protocol supports the nerve environment by focusing on:
- 🩸 Microcirculation
- ⚡ Nerve signaling stability and repair support
- 🌿 Inflammation and oxidative stress reduction
- 🧠 Metabolic and recovery foundations
If B12 deficiency or another nutritional issue is suspected, that should be coordinated with appropriate testing and medical guidance. The goal is not guessing. The goal is identifying every correctable driver of nerve irritation.
When to seek evaluation sooner
Seek evaluation if you have:
- rapidly worsening numbness
- balance decline
- weakness
- symptoms in both hands and feet
- cognitive changes
- anemia history
- symptoms despite improving blood sugar
- wounds or reduced protective sensation
FAQs
Can B12 deficiency cause neuropathy symptoms?
Yes. B12 deficiency can contribute to neurological symptoms such as tingling, numbness, weakness, and balance problems.
Can metformin affect B12 levels?
Long-term metformin use is associated with lower B12 levels in some patients, so testing may be appropriate when symptoms suggest deficiency.
Does better A1C always fix neuropathy?
Not always. Nerve recovery can be slow, and other drivers such as B12 deficiency, inflammation, or compression may contribute.
Should I take B12 without testing?
Discuss testing and supplementation with your provider, especially if symptoms are progressing or you take medications that may affect B12.
References
- NCBI Bookshelf / NIH: Vitamin B12 deficiency and neurologic symptoms
- UK MHRA drug safety update: Metformin and reduced vitamin B12 levels
- NINDS: Peripheral Neuropathy overview
Clinic: Neuropathy Relief Center of Miami
Address: 8585 Sunset Drive, Suite 104, Miami, FL 33143
Call: 305-274-7475
Learn more: Neuropathy Treatment Miami
Book your consultation today: Appointments
Sincerely Yours for Health,
Dr. Rodolfo Alfonso, D.C.
8585 Sunset Drive,
STE 104
Miami, FL 33143
Ph: 305-275.7475
www.neuropathyreliefmia