Does B12 Help with Excessive Sweating? A Comprehensive Guide

November 21, 2025 •

4 min read

According to the International Hyperhidrosis Society, excessive sweating affects approximately 4.8% of the global population. For some individuals, a nutritional imbalance could be the root cause, leading many to ask: does B12 help with excessive sweating? The evidence suggests a complex relationship, particularly in cases where deficiency impacts nervous system function.

Quick Summary

Examines the nuanced connection between vitamin B12 levels and excessive sweating, detailing how a deficiency can impair nervous system function and affect sweat gland activity.

Key Points

Deficiency Can Cause Sweating: Low Vitamin B12 can impair nerve function, potentially leading to excessive sweating, particularly night sweats, through its effect on the autonomic nervous system.
Not a Universal Cure: B12 is not a direct remedy for all types of hyperhidrosis, as other factors like genetics, medication, or other medical conditions can be the cause.
Nervous System Link: B12 is crucial for nerve health; a deficiency can damage the nerves controlling sweat glands, leading to abnormal sweating responses.
Medical Diagnosis is Key: It is essential to get a medical evaluation to determine if a B12 deficiency is causing your symptoms rather than self-diagnosing and self-treating.
Supplementation Considerations: While helpful for deficiency, B12 injections or high doses can sometimes have the side effect of increasing sweating or causing hot flashes in rare instances.
Evaluate Other Symptoms: Consider if other B12 deficiency symptoms, such as fatigue, tingling, or memory issues, are present alongside the excessive sweating.

The Surprising Link Between B12 Deficiency and Sweating

While vitamin B12 is not a cure-all for excessive sweating (known as hyperhidrosis), there is a significant body of anecdotal evidence and several case studies linking B12 deficiency to the condition. This is especially true for night sweats. The connection lies in B12's crucial role in maintaining a healthy nervous system. When levels are low, it can lead to neurological issues that affect the body's autonomic functions, including the regulation of sweat glands.

The B12-Nervous System Connection

Vitamin B12, or cobalamin, is vital for several bodily processes, but its function within the nervous system is particularly relevant to excessive sweating. It is essential for producing and maintaining the myelin sheath, a protective layer that insulates nerve fibers. This sheath ensures that nerve signals are transmitted correctly and efficiently. A B12 deficiency can cause demyelination, damaging the nerves and impairing their ability to function properly.

The autonomic nervous system controls involuntary functions, such as heart rate, digestion, and sweating. If the nerves controlling sweat glands are affected by a B12 deficiency, it could lead to the overproduction of sweat, even in non-stressful or cool conditions. This is a plausible explanation for why some individuals experience sweating as a symptom of their deficiency.

Evidence from Case Studies

Reports have documented cases where patients with excessive sweating, particularly night sweats, found significant relief after receiving vitamin B12 therapy. For example, one journal discussed three cases where drenching night sweats were attributed to B12 deficiency, with all patients responding dramatically to treatment. Another report noted a patient with long-standing, drenching night sweats who responded positively to B12 injections. These cases support the theory that for some people, addressing an underlying B12 deficiency can resolve or significantly improve excessive sweating symptoms. It is important to note, however, that these are specific instances and do not mean B12 is a universal cure for all forms of hyperhidrosis.

Other Potential Causes of Excessive Sweating

To understand if a B12 deficiency is the cause of your symptoms, it's helpful to consider other possibilities. Many factors can trigger or cause excessive sweating, and a medical professional can help differentiate between them. Here are a few common causes:

Medical Conditions: Underlying health issues like menopause, diabetes, hyperthyroidism, and certain infections can trigger sweating.
Medication Side Effects: Some medications, including certain antidepressants and beta-blockers, can list excessive sweating as a side effect.
Primary Focal Hyperhidrosis: In this most common form, excessive sweating is localized to specific areas like the hands, feet, or underarms, and has no identifiable medical cause.
Anxiety and Stress: Psychological factors can trigger or exacerbate sweating in individuals, particularly in stressful situations.

Vitamin B12 Supplementation and Potential Side Effects

While supplementing with B12 can be beneficial if a deficiency is confirmed, it's not without potential side effects. In some rare cases, individuals receiving B12 injections have reported increased sweating or hot flashes. This highlights the importance of consulting a doctor before self-treating. High doses of B12 supplements are generally considered safe, but the best approach is to identify and treat the root cause of your symptoms under medical supervision.

Comparison of B12-Related vs. Other Sweating

To help clarify the differences, here is a comparison of B12-related sweating versus other types of hyperhidrosis.


Characteristic	B12 Deficiency-Related Sweating	Primary (Focal) Hyperhidrosis	Secondary Hyperhidrosis (Other Causes)
Symptom Profile	Often accompanied by neurological symptoms (fatigue, tingling), sometimes with night sweats.	Usually localized to specific areas (palms, feet, underarms) without a clear cause.	Often generalized and linked to another medical condition (e.g., hyperthyroidism, menopause).
Underlying Cause	Impaired nervous system function due to vitamin deficiency.	Overactive sympathetic nervous system, exact cause unknown.	Hormonal changes, metabolic disorders, medications, or other systemic diseases.
Treatment Approach	Correcting the deficiency with supplements or injections.	Prescription antiperspirants, iontophoresis, Botox, or oral medications.	Addressing the underlying medical condition.

When to Talk to a Doctor

If you are experiencing unexplained excessive sweating, it's crucial to consult a healthcare professional. A doctor can order blood tests to check your B12 levels and help determine the underlying cause. This is the most reliable way to create an effective treatment plan. They can also provide guidance on potential therapies for diagnosed hyperhidrosis if a deficiency isn't the issue.

Key Symptoms of a B12 Deficiency

For those considering a possible link, here are some common symptoms of B12 deficiency to look out for in addition to excessive sweating:

Feeling very tired or weak
Numbness or tingling in the hands and feet
Pale skin
Memory problems or difficulty concentrating
A sore, red tongue
Changes in mood, including irritability or depression

Food Sources of Vitamin B12

Maintaining adequate B12 intake is important for overall health. Excellent dietary sources include:

Meat (especially red meat)
Fish and shellfish
Dairy products like milk and cheese
Eggs
Fortified breakfast cereals
Some fortified plant-based milk alternatives

Conclusion

While a vitamin B12 deficiency can be a contributing factor to excessive sweating, particularly night sweats, it is not a cure for all forms of hyperhidrosis. The link is tied to B12's essential role in nerve function. If you suspect a deficiency, a medical consultation and proper testing are the first steps toward an accurate diagnosis and effective treatment. Relying on B12 supplementation alone without a confirmed deficiency is not a recommended or reliable solution for managing excessive sweating symptoms.

For more detailed information on Vitamin B12, you can visit the NIH Factsheet.

Frequently Asked Questions

B12 injections can resolve excessive sweating if the sweating is caused by a vitamin B12 deficiency. Several case reports have shown a dramatic reduction in night sweats following B12 injections in deficient patients. However, if the sweating is due to another cause, the injections will likely have no effect.

B12 is essential for the health of the nervous system, including the proper function of nerves that control sweat glands. A deficiency can cause demyelination and damage these nerves, leading to an impaired or overactive signaling to the sweat glands and causing excessive perspiration.

Yes, a deficiency in vitamin B12 is known to cause night sweats in some individuals. Several case studies have documented this link, with patients' symptoms resolving after B12 therapy. Other vitamins, such as vitamin D, have also been suggested to play a role.

Besides potentially causing excessive sweating, B12 deficiency symptoms include fatigue, weakness, numbness or tingling in the hands and feet, memory problems, a sore or red tongue, and mood changes like irritability or depression.

Yes, in some rare instances, B12 supplementation, especially through injections, has been reported to cause increased sweating or hot flashes as a side effect. If you experience this, you should consult a doctor.

You should not take a B12 supplement without first consulting a doctor to get a proper diagnosis. A medical professional can perform tests to see if a deficiency is present. If your sweating is caused by another condition, B12 supplementation may not be effective and could have unnecessary side effects.

B12-related sweating is caused by a specific nutritional deficiency and is often accompanied by other neurological symptoms, sometimes presenting as generalized or night sweats. Primary hyperhidrosis is a condition of unknown cause, typically localized to specific areas like palms and underarms, and is not linked to a deficiency.