What Does Nerve Damage From B12 Deficiency Feel Like?

October 14, 2025 •

4 min read

Over time, a vitamin B12 deficiency can cause significant harm to the nervous system, potentially leading to irreversible damage if left untreated. Many people wonder, "what does nerve damage from B12 deficiency feel like?" The sensation is often described as strange tingling, numbness, or a 'pins and needles' feeling, primarily affecting the hands and feet.

Quick Summary

Nerve damage from B12 deficiency typically presents as pins and needles, numbness, or a burning sensation, especially in the hands and feet. This peripheral neuropathy can progress to muscle weakness, balance problems, and cognitive difficulties. Symptoms often start gradually and can worsen over time without proper intervention.

Key Points

Initial Tingling and Numbness: Early nerve damage from B12 deficiency often starts with a 'pins and needles' or numb feeling, usually beginning in the hands or feet.
Balance and Coordination Issues: As the deficiency progresses, damage to the nerves affecting balance can lead to difficulty walking or an unsteady gait (ataxia).
Cognitive and Psychological Effects: B12 deficiency can also impact the brain, causing memory loss, confusion, and mood changes like depression or irritability.
Potential for Irreversible Damage: If left untreated for too long, nerve damage from B12 deficiency can become permanent, particularly in older individuals.
Treatment Can Reverse Symptoms: Early and consistent treatment with B12 supplementation can halt the progression of nerve damage and, in many cases, reverse the symptoms.
Gradual Onset: Symptoms often develop slowly over months or years, making them easy to miss until they become more severe.

The Progression and Symptoms of B12 Deficiency Nerve Damage

Vitamin B12 is vital for the health of the nervous system, playing a critical role in the formation of myelin, the protective sheath that surrounds nerves. When B12 levels are low, this sheath can begin to deteriorate, disrupting the proper transmission of nerve signals. The resulting nerve damage, known as peripheral neuropathy, produces a distinct set of sensations that tend to appear gradually and intensify over time.

Early signs of peripheral neuropathy

The initial symptoms of nerve damage from a B12 deficiency can be subtle, making them easy to overlook or mistake for other conditions. Common early manifestations include:

Pins and needles (paresthesia): This is often one of the first and most common signs. Many describe it as a tingling or prickling sensation, similar to when a limb 'falls asleep'.
Numbness: A progressive loss of sensation can follow the tingling. This typically starts in the hands or feet and can spread upwards.
Burning sensation: Some individuals report a persistent, burning pain, particularly in their extremities.
Unsteady gait: Damage to the nerves responsible for balance can lead to a clumsy or uncoordinated walk, also known as ataxia.
Reduced sense of position: Individuals may become less aware of where their limbs are in space, which can contribute to balance problems.

Advanced and severe neurological complications

If a B12 deficiency remains untreated, the nerve damage can become more severe and impact other parts of the nervous system, including the spinal cord. In advanced cases, the symptoms can become more pronounced and debilitating:

Significant muscle weakness: The nerve damage can progress to affect motor nerves, resulting in substantial weakness in the limbs.
Cognitive issues: B12 deficiency can affect the brain, leading to memory loss, difficulty concentrating, confusion, and impaired judgment.
Psychological problems: Mood changes, including depression, irritability, and in severe cases, psychosis or dementia, can occur.
Loss of reflexes: Deep tendon reflexes may diminish or disappear as nerve function declines.
Visual disturbances: Damage to the optic nerve can cause vision problems or even loss of vision.

Nerve damage from B12 deficiency vs. other conditions

It is important to differentiate the symptoms of B12 deficiency from other forms of neuropathy. The presentation of nerve damage can vary depending on the underlying cause. The following table compares key characteristics of B12 deficiency neuropathy with diabetic neuropathy, another common cause.


Feature	B12 Deficiency Neuropathy	Diabetic Neuropathy
Onset of symptoms	Often gradual, worsening over months or years.	Often gradual, but can have a more rapid onset depending on blood sugar control.
Primary sensation	Pins and needles, numbness, burning, loss of position sense.	Numbness, tingling, pain (often burning, sharp, or cramping), loss of sensation.
Common location	Hands and feet, often starting in the feet and spreading upwards.	Most commonly starts in the feet and lower legs.
Associated symptoms	Fatigue, weakness, anemia, cognitive issues, mood changes.	Fatigue, weakness, increased urination, thirst, and slow-healing sores.
Cause	Lack of intrinsic factor (pernicious anemia), malabsorption, or dietary insufficiency.	High blood sugar levels damaging nerve fibers over time.
Reversibility	Symptoms may be reversible if caught and treated early, but long-term damage can be permanent.	Control of blood sugar can prevent further damage, but existing damage may be irreversible.

The mechanism behind the feeling

The specific sensations of B12 deficiency nerve damage are directly linked to its role in myelin maintenance. Myelin acts as an insulator for nerve fibers, allowing electrical signals to travel quickly and efficiently. When B12 levels are low, the body cannot produce enough myelin, and the existing sheath breaks down (demyelination). This exposes the nerves, leading to erratic or slowed signaling. The brain interprets this abnormal nerve activity as tingling, numbness, or burning, and the disrupted communication with muscles can lead to weakness and balance issues.

In severe cases, B12 deficiency can cause a serious condition called subacute combined degeneration, which involves demyelination and damage to the spinal cord. This can result in severe coordination problems and other serious neurological symptoms. Early diagnosis is crucial because if left untreated for too long, the nerve damage can become permanent, even with subsequent B12 supplementation.

Conclusion

Nerve damage from B12 deficiency is a serious condition with symptoms that can range from mild tingling to severe neurological and cognitive impairment. The characteristic 'pins and needles,' numbness, and balance issues are key indicators that something is wrong. Due to the gradual onset of symptoms, it is essential for at-risk individuals, such as the elderly or vegans, to be aware of the signs and seek medical advice promptly. Early and consistent treatment, often involving supplements or injections, can prevent the progression of nerve damage and improve or reverse many of the symptoms. Regular monitoring is key to maintaining neurological health and quality of life.

Resources for further information

For more in-depth information about the effects of B12 deficiency on the nervous system, you can consult reputable medical sources. The National Institutes of Health (NIH) provides a comprehensive professional fact sheet on Vitamin B12 and its effects.

Frequently Asked Questions

Nerve damage may become permanent if the B12 deficiency is left untreated for an extended period, particularly in severe cases or in older adults. The best way to know is to see a doctor, who can assess your symptoms and the duration of your deficiency to determine the potential for recovery with treatment.

Yes, if diagnosed and treated early, many symptoms of B12 deficiency nerve damage, such as tingling and numbness, can be improved or reversed. The outcome depends heavily on the severity and duration of the deficiency.

Treatment for B12 deficiency depends on the underlying cause. For severe deficiencies or absorption problems, intramuscular injections are often the fastest and most effective way to restore B12 levels. Milder cases may be managed with high-dose oral supplements or dietary changes.

Nerve damage from B12 deficiency typically starts in the peripheral nerves, which are located outside the brain and spinal cord. This often manifests as tingling or numbness that begins in the hands and feet and can spread upwards.

A severe lack of B12 can cause significant issues in the legs, including tingling, numbness, pain, and muscle weakness. Damage to the spinal cord can also affect motor skills, leading to problems with balance and walking.

Yes, B12 deficiency can significantly impact the brain and nervous system. It can cause cognitive problems like memory loss, difficulty concentrating, and confusion. In severe, prolonged cases, it can lead to more serious conditions like dementia or psychosis.

With proper treatment, improvement can take weeks to months, and sometimes longer. Neurological symptoms are often slower to resolve than other symptoms, and full recovery is not always guaranteed if the damage was severe or long-standing.