Does B12 Lower Inflammation? Understanding the Connection

November 19, 2025 •

3 min read

According to a 2023 study published in the Journal of the Science of Food and Agriculture, individuals with higher circulating vitamin B12 levels tend to have lower concentrations of inflammatory markers. This inverse relationship is a key area of research, suggesting that adequate vitamin B12 intake could play a significant role in managing inflammatory processes and overall health.

Quick Summary

The relationship between vitamin B12 and inflammation is complex, but evidence suggests an inverse association exists. B12 is essential for metabolic processes that prevent the accumulation of pro-inflammatory compounds, and its deficiency is linked to higher inflammation and oxidative stress.

Key Points

Inverse Relationship: Higher vitamin B12 levels are frequently associated with lower concentrations of inflammatory markers like IL-6 and CRP.
Homocysteine Reduction: B12 is essential for converting homocysteine into methionine; a deficiency can cause homocysteine accumulation, which promotes inflammation.
Antioxidant Effects: Vitamin B12 acts as an antioxidant, helping to reduce oxidative stress that can both trigger and exacerbate inflammation.
Deficiency Link: B12 deficiency, often caused by dietary restrictions or malabsorption, is connected to chronic inflammation and increased risk for conditions like heart disease.
Methylcobalamin's Role: The active form of B12, methylcobalamin, has been shown to modulate neuroinflammation, offering potential benefits for chronic neuropathic pain.
Supplementation Considerations: Correcting a B12 deficiency with supplements or diet can help lower inflammation, but the approach depends on the underlying cause, especially in autoimmune conditions.

The Anti-Inflammatory Mechanisms of Vitamin B12

Vitamin B12 influences the body's inflammatory response primarily through its role in managing homocysteine levels, its antioxidant properties, and its impact on cytokine regulation.

Homocysteine Metabolism

Vitamin B12 is crucial for breaking down homocysteine. High levels of homocysteine (hyperhomocysteinemia) are linked to increased inflammation and a higher risk of cardiovascular disease, stroke, and dementia. B12, with B6 and folate, converts homocysteine into methionine. A B12 deficiency disrupts this process, causing homocysteine to build up and trigger inflammation.

Antioxidant Properties

Vitamin B12 has antioxidant effects that help combat oxidative stress, an imbalance between free radicals and antioxidants that can worsen inflammation. B12 can help reduce oxidative damage. A 2024 study on maternal B12 supplementation showed reduced oxidative stress markers.

Cytokine Modulation

B12 may also modulate cytokine activity. Cytokines are proteins important in immune and inflammatory responses. Methylcobalamin, an active form of B12, may regulate NFκB, a protein complex that controls pro-inflammatory cytokines like TNF-α and IL-6.

The Link Between B12 Deficiency and Chronic Inflammation

A deficiency in vitamin B12 can contribute to chronic inflammation due to its role in metabolic pathways. This can lead to various health issues.

Consequences of Deficiency

Cardiometabolic risks: Studies show an inverse correlation between B12 levels and inflammatory markers like CRP and IL-6 in those at high cardiovascular risk. Correcting a deficiency might reduce these risks.
Autoimmune conditions: Conditions like autoimmune gastritis can cause B12 malabsorption. While supplementation treats the deficiency, it doesn't typically treat the autoimmune disease itself unless the deficiency is contributing to inflammation.
Neuropathic pain: B12 supplementation, especially methylcobalamin, has shown potential in modulating neuroinflammation and reducing pain in chronic neuropathic pain cases.

Evidence from Scientific Studies

Research consistently shows a link between vitamin B12 status and inflammatory markers. Studies have indicated:

Type 2 diabetic omnivores with higher B12 had lower IL-6 levels.
Maternal B12 supplementation in Bangladesh reduced oxidative stress and modulated cytokines.
An inverse relationship was observed between circulating B12 and chronic inflammation in humans and mice, with higher B12 linked to lower IL-6 and CRP.

How to Maintain Optimal B12 Levels for Reducing Inflammation

Maintaining sufficient B12 is important for health and managing inflammation, especially if deficient. Strategies include:

Dietary Sources

Vitamin B12 is found in animal products and fortified foods:

Meat, poultry, fish
Eggs
Milk and dairy products
Fortified cereals and nutritional yeast

Supplementation

Supplementation is often needed for those with dietary restrictions or absorption issues. Options include tablets, lozenges, and injections.

Comparison of B12 Sources for Inflammatory Benefits


Feature	B12 from Food	B12 from Supplements	B12 Injections
Absorption	Requires stomach acid and intrinsic factor for absorption.	High doses can be absorbed passively without intrinsic factor.	Bypass digestive system for immediate and complete absorption.
Effect on Homocysteine	Helps break down homocysteine as part of a balanced diet.	Effective in lowering homocysteine levels, especially in deficiencies.	Most effective for severe deficiencies or malabsorption issues.
Mechanism	Contributes to normal metabolic functions that prevent inflammation.	Addresses deficiencies that can trigger inflammation and supports immune modulation.	Can provide rapid and high-dose support to modulate neuroinflammation.
When to use	Daily intake for general health and prevention of deficiency.	For individuals with mild deficiency, restricted diets, or reduced absorption.	Necessary for cases of pernicious anemia and severe malabsorption.

Conclusion: The Final Word on B12 and Inflammation

Evidence indicates a significant link between B12 and inflammation. Adequate B12 supports metabolic processes that regulate inflammation, preventing homocysteine buildup and acting as an antioxidant. For those with a B12 deficiency, correcting it can reduce inflammatory markers and risks. Consult a healthcare professional for appropriate action, especially for chronic inflammatory conditions.

For more information, visit the National Institutes of Health Office of Dietary Supplements.

Frequently Asked Questions

The primary way vitamin B12 helps lower inflammation is by regulating homocysteine metabolism. It helps convert the amino acid homocysteine into methionine, preventing the pro-inflammatory effects of elevated homocysteine levels.

Yes, a B12 deficiency can contribute to chronic inflammation. The resulting high homocysteine levels create oxidative stress, which triggers and promotes inflammatory responses in the body.

Yes, B12 supplements can be effective for reducing inflammation, particularly when a deficiency is the root cause. Studies have shown that supplementation can lower inflammatory markers and oxidative stress, especially in deficient individuals.

For autoimmune-related inflammation, B12 can help address a deficiency that may result from the condition, such as pernicious anemia. Correcting the deficiency can improve symptoms, but B12 is not considered a treatment for the underlying autoimmune process itself.

Common causes include dietary insufficiency (especially in vegetarians and vegans), malabsorption issues like gastritis or Crohn's disease, and autoimmune conditions like pernicious anemia.

B12 injections are most often used for severe deficiencies or malabsorption issues, which can be linked to inflammation. By restoring B12 levels rapidly and effectively, they can help lower inflammation associated with the deficiency, especially in neuropathic pain.

Methylcobalamin is the biologically active form of vitamin B12 and has been shown to modulate neuroinflammation. However, correcting a deficiency with any standard form, such as cyanocobalamin, can also effectively lower inflammation caused by high homocysteine.