What are the symptoms of B12 deficiency in legs? Recognizing the Signs of Neuropathy

October 1, 2025 •

3 min read

According to the National Institutes of Health (NIH), a vitamin B12 deficiency can often lead to nerve damage, which can first appear in the legs and feet. Understanding what are the symptoms of B12 deficiency in legs is vital for early detection and intervention, as prolonged nerve damage can become irreversible.

Quick Summary

Vitamin B12 deficiency can manifest with neurological symptoms in the legs, including tingling, numbness, burning sensations, and difficulty walking. Early recognition of these signs is important, and treatment often involves addressing the root cause through diet or supplementation to prevent further nerve damage.

Key Points

Neurological Signs: Look for tingling, numbness, and burning sensations in the legs and feet, as these are primary indicators of nerve damage caused by B12 deficiency.
Gait and Balance Issues: Difficulty with walking, unsteadiness, and poor coordination can signal that a B12 deficiency is affecting the nervous system.
Anemia and Pallor: Accompanying symptoms often include fatigue, general weakness, and pale or yellowish skin due to the effect of low B12 on red blood cell production.
Common Risk Factors: Individuals who follow vegan diets, are over 50, or have conditions like pernicious anemia or Crohn's disease are at a higher risk of developing a deficiency.
Irreversible Damage: Prompt diagnosis and treatment are crucial because nerve damage from prolonged B12 deficiency can sometimes become permanent.
Treatment Options: Treatment for B12 deficiency can include injections for severe cases or oral supplements for milder, diet-related issues.

The Neurological Impact of Vitamin B12

Vitamin B12 is essential for various bodily functions, particularly nerve tissue health, brain function, and red blood cell production. It plays a key role in maintaining the myelin sheath, which protects nerve fibers and ensures efficient nerve impulse transmission. A lack of B12 can cause myelin breakdown, leading to nerve damage and neurological problems. The legs and feet are often the initial areas affected.

Symptoms of B12 Deficiency in the Legs

Nerve damage symptoms from B12 deficiency often begin subtly and worsen over time. These can include a combination of sensations in the legs and feet, such as numbness, tingling, and a burning sensation. Muscle weakness, balance problems (ataxia), and abnormal gait can also occur. Other potential symptoms include restless legs syndrome, a feeling of cold feet, and diminished sensation.

Other Related Symptoms to Watch For

Beyond leg symptoms, B12 deficiency can cause systemic issues like fatigue, weakness, cognitive problems (memory issues, difficulty concentrating), and anemia (pale or yellowish skin). Mood changes (irritability, depression, confusion) and a swollen, red tongue (glossitis) are also possible.

Causes of B12 Deficiency

A deficiency can result from factors beyond insufficient dietary intake, often involving poor absorption. Common causes include pernicious anemia, dietary factors (especially for vegans), age-related reduced stomach acidity, digestive disorders (Crohn's, celiac disease), certain surgeries (gastric bypass), and medications (heartburn drugs, metformin). Excessive alcohol use can also impair B12 absorption.

Treatment and Prevention

Treatment for a B12 deficiency depends on its severity and cause. Mild cases may improve with oral supplements, while more severe deficiencies, particularly those with neurological symptoms or malabsorption, might require injections. Treatment options include B12 injections for serious deficiencies or absorption problems, often prescribed lifelong if the cause is permanent. High-dose oral supplements can be effective for milder deficiency. Dietary changes, focusing on B12-rich foods or fortified products, are vital for management and prevention. Preventative measures include a balanced diet, supplementation for at-risk groups (vegans, older adults, those on certain medications), and regular check-ups to monitor B12 levels, as early detection is crucial to prevent irreversible nerve damage.

Comparison: B12 Deficiency Neuropathy vs. Diabetic Neuropathy

Neuropathy in the legs can have various causes, including B12 deficiency and diabetes. B12 deficiency symptoms can resemble diabetic neuropathy. For further information, the National Institute of Neurological Disorders and Stroke (NINDS) offers resources on peripheral neuropathy. {Link: ninds.nih.gov https://www.ninds.nih.gov/health-information/disorders/peripheral-neuropathy}


Feature	B12 Deficiency Neuropathy	Diabetic Neuropathy
Sensation	Tingling, numbness, burning, and loss of position sense often begin in feet and legs.	Numbness, tingling, or burning pain, particularly in the feet and lower legs.
Onset	Develops gradually, with symptoms worsening over time.	Can be a long-term complication of poorly controlled diabetes.
Associated Symptoms	Fatigue, anemia, glossitis, and cognitive issues are common.	Foot ulcers, digestive problems, and vision changes may occur.
Cause	Primarily due to insufficient intake or absorption of B12.	Caused by chronic high blood sugar damaging nerves.
Treatment Focus	Increasing B12 levels through supplements or injections.	Managing blood sugar, medication, and lifestyle changes.
Reversibility	Symptoms can often improve with treatment, but severe or prolonged nerve damage may be permanent.	Nerve damage may be slowed but is not always fully reversible.

Conclusion

While general fatigue is a common symptom of B12 deficiency, the neurological signs in the legs serve as a critical warning. Tingling, numbness, pain, and balance issues indicate nerve damage that can become permanent if untreated. Understanding the causes and recognizing these specific symptoms are key to effective management. If you suspect a deficiency, consult a healthcare professional for diagnosis and treatment, which may include dietary changes or injections. Prompt action can help prevent long-term neurological complications.

Frequently Asked Questions

Yes, B12 deficiency can cause nerve-related pain in the legs, including burning sensations and general discomfort, as it impairs the proper function of nerve fibers.

The 'pins and needles' or tingling sensation (paraesthesia) is caused by nerve damage due to a lack of B12. This deficiency can cause the protective myelin sheath covering the nerves to deteriorate, disrupting normal nerve signals.

Yes, severe B12 deficiency can damage nerves, leading to coordination and balance problems. This condition, known as ataxia, can result in an unsteady or staggering gait.

Yes, feeling unusually cold in the feet, even in warm conditions, can be a symptom. This may indicate poor circulation and nerve issues linked to low B12 levels affecting red blood cell production.

Diagnosis is typically confirmed with blood tests that measure B12 levels. Further testing may be necessary to identify the underlying cause of the deficiency.

Common causes include pernicious anemia, following a vegan diet without supplementation, decreased stomach acid in older adults, and certain medical conditions or medications.

Treatment varies based on the severity and cause. It can involve oral supplements or, in more severe cases or with absorption issues, regular B12 injections.

While some symptoms may improve relatively quickly, nerve-related symptoms in the legs often take longer to show improvement and may not fully resolve if the damage is severe or long-standing.