Which vitamin deficiency causes Bell's palsy? Unpacking the nutritional links

October 6, 2025 •

4 min read

According to the National Institute of Neurological Disorders and Stroke, Bell's palsy is the most common cause of facial paralysis, affecting up to 40,000 people in the U.S. each year. This condition often has no known cause, leading many to question, 'Which vitamin deficiency causes Bell's palsy?'.

Quick Summary

The exact cause of Bell's palsy is unknown, though inflammation and viral infections are suspected triggers. While not a direct cause, deficiencies in certain vitamins, such as B12, C, and D, may influence the severity and recovery time.

Key Points

Not a direct cause: Bell's palsy is often idiopathic and triggered by viral inflammation, not a single vitamin deficiency.
B12 and recovery: Vitamin B12, particularly in injection form, has been shown to potentially accelerate recovery of facial nerve function.
Vitamin D and severity: Studies link lower vitamin D levels with higher severity of Bell's palsy and slower recovery.
Vitamin C as a risk factor: A severe vitamin C deficiency has been reported as a potential risk or triggering factor for Bell's palsy.
Supportive nutrition: A diet rich in B vitamins, omega-3 fatty acids, and antioxidants supports nerve health and can aid in the recovery process.
Immune system link: Since some vitamin deficiencies can weaken the immune system, they might indirectly increase the risk of viral reactivation, a proposed trigger for Bell's palsy.
Dietary modifications: If chewing is difficult, softer, easy-to-eat foods should be prioritized to ensure proper nutrition during recovery.

Is there a specific vitamin deficiency that causes Bell's palsy?

The short answer is no; no single vitamin deficiency has been definitively proven to cause Bell's palsy. The condition is described as idiopathic, meaning it has no known cause. The current leading theory suggests that Bell's palsy is triggered by a viral infection that causes inflammation and swelling of the seventh cranial nerve, which controls facial muscles. The herpes simplex virus, known for causing cold sores, is the most frequently implicated viral culprit. While a specific deficiency isn't the root cause, a lack of certain vitamins can weaken the body's immune response or impact nerve regeneration, potentially influencing the condition's onset, severity, or recovery.

The viral link and inflammation

Many researchers believe that a latent viral infection, such as herpes simplex, becomes reactivated during periods of stress, illness, or fatigue. This reactivation can lead to inflammation and swelling of the facial nerve as it passes through a narrow bony channel in the skull. The resulting compression damages the nerve's ability to transmit signals, causing the characteristic facial weakness or paralysis. A healthy immune system is key to keeping these viruses in check, and deficiencies in certain vitamins can compromise immunity, making a person more susceptible to these triggers.

How key vitamins influence Bell's palsy

Different vitamins play distinct roles in nerve health and immune function. Here's what current research suggests about the involvement of specific vitamin deficiencies in Bell's palsy:

Vitamin B12: This vitamin is crucial for the health of the nervous system. It is responsible for maintaining the myelin sheath, the protective coating that surrounds nerve fibers. Low levels of B12 can lead to nerve damage, and some studies have shown that B12 injections may help accelerate recovery in Bell's palsy patients. A deficiency would hinder the body's natural nerve repair process, potentially prolonging recovery.
Vitamin D: A meta-analysis published in 2025 found a significant association between lower serum vitamin D levels and higher grades of Bell's palsy severity. Vitamin D functions as a neuro-immuno-modulator and has anti-inflammatory effects, which could benefit recovery given the inflammatory nature of the condition. While not a cause, a deficiency could lead to a less favorable prognosis.
Vitamin C: A 2022 case report suggested that severe vitamin C deficiency could be a risk or triggering factor for Bell's palsy. Vitamin C is a powerful antioxidant and immunomodulator that helps protect against oxidative stress and supports immune function. A deficiency could lead to impaired immunity, potentially increasing the risk of viral reactivation that triggers the palsy.

Supporting nerve health with a balanced diet

Although dietary changes won't cure Bell's palsy, proper nutrition can support nerve regeneration and a healthy immune system during recovery. A well-balanced diet rich in vitamins and anti-inflammatory compounds is recommended. Specific dietary advice, such as consuming soft, easy-to-chew foods, may also be necessary if facial paralysis affects eating and swallowing.

Comparison of Key Vitamins and their Role in Bell's Palsy


Vitamin	Primary Role in Nerve Health	Link to Bell's Palsy	Food Sources
B12 (Cobalamin)	Maintains the myelin sheath; nerve fiber regeneration.	May speed up recovery, especially with injections.	Meat, fish, poultry, eggs, dairy, fortified cereals.
D	Neuro-immuno-modulator; anti-inflammatory effects.	Low levels associated with more severe cases and poorer recovery.	Sunlight, fortified milk, fatty fish (salmon, mackerel).
C (Ascorbic Acid)	Antioxidant; immune system support; neural regeneration.	A potential risk factor; deficiency may trigger viral reactivation.	Citrus fruits, berries, leafy greens, broccoli.
B1 (Thiamine)	Converts carbs to energy for nerves.	General nerve health support; part of B-complex supplements.	Whole grains, fish, legumes, seeds.
B6 (Pyridoxine)	Helps transmit nerve signals effectively.	General nerve health support; part of B-complex supplements.	Chickpeas, fish, poultry, bananas.
Omega-3s	Reduce inflammation; protect nerves.	May aid recovery by mitigating inflammation.	Fatty fish, flaxseeds, walnuts.

Nutritional strategies for recovery

For those affected by Bell's palsy, incorporating a nutrient-dense, anti-inflammatory diet can be a valuable part of the recovery process. While not a cure, this approach helps support the body's healing mechanisms. Consider the following:

Prioritize B-Vitamins: Ensure adequate intake of B-vitamins, especially B12, B1, and B6. Rich sources include lean meats, fish, eggs, dairy, and leafy green vegetables. For individuals with a diagnosed B12 deficiency or specific absorption issues (like pernicious anemia), injections may be necessary.
Increase Antioxidant Intake: Viruses and inflammation are central to Bell's palsy. Antioxidant-rich foods, particularly those high in Vitamin C, can help neutralize oxidative stress and support the immune system. Good sources include berries, citrus fruits, and colorful vegetables.
Focus on Anti-inflammatory Foods: Incorporate foods that combat inflammation to aid nerve repair. This includes fatty fish rich in omega-3 fatty acids, turmeric, ginger, and green tea.
Consume Easy-to-Eat Foods: If chewing and swallowing are difficult, focus on soft, puréed, or liquid foods like soups, smoothies, yogurt, mashed vegetables, and pasta.
Consider Supplements (with medical guidance): If lab tests confirm a deficiency, your doctor may recommend supplementation. As noted, vitamin B12 injections have been studied for recovery, and vitamin D may be beneficial, but any supplementation should be discussed with a healthcare provider.

Conclusion: Nutrition as a supportive tool

In conclusion, no single vitamin deficiency directly causes Bell's palsy, which is most likely triggered by a viral infection leading to nerve inflammation. However, nutritional status plays a supportive role in both prevention and recovery. Ensuring adequate levels of key vitamins, particularly B12, B1, B6, C, and D, can bolster the immune system and support nerve health. While treatment typically involves corticosteroids, a focus on a healthy, anti-inflammatory diet provides the body with the resources it needs to heal. For specific concerns about a vitamin deficiency, it is always best to consult a healthcare professional.

For additional information on managing Bell's palsy, you can visit the Facial Palsy UK website.

Frequently Asked Questions

A low vitamin B12 level is not a direct cause of Bell's palsy, but it can negatively impact nerve health. Since Bell's palsy involves damage to the facial nerve, sufficient B12 is important for nerve regeneration and recovery.

Research has found that lower serum vitamin D levels are associated with more severe cases of Bell's palsy and less complete recovery. As a neuro-immuno-modulator, vitamin D has anti-inflammatory properties that may help manage the inflammation associated with the condition.

Yes, some evidence suggests a link. A case report indicated that a severe vitamin C deficiency could be a risk or triggering factor. As an antioxidant and immune booster, adequate vitamin C may help the body combat viral triggers that are thought to lead to Bell's palsy.

Focus on an anti-inflammatory diet rich in B vitamins, antioxidants, and omega-3 fatty acids. Good options include fatty fish, leafy greens, nuts, seeds, eggs, and citrus fruits. If chewing is difficult, opt for soft, easy-to-eat foods.

Some studies suggest that B12 injections (methylcobalamin) may lead to faster recovery, particularly when combined with corticosteroids. However, the efficacy compared to standard treatment is still being evaluated, and injections should only be administered under a doctor's supervision.

The main cause of Bell's palsy is not fully understood, but viral infections, particularly with the herpes simplex virus, are considered the most likely trigger. The virus is thought to cause inflammation and swelling of the facial nerve, leading to paralysis.

There is no definitive way to prevent Bell's palsy. However, maintaining a strong immune system and healthy nerve function through a balanced, nutrient-rich diet, and managing other risk factors like diabetes and hypertension, may reduce susceptibility.