Can Vitamin B12 Deficiency Cause Grey Hair? Unpacking the Link

October 25, 2025 •

4 min read

Research has noted that vitamin B-12 deficiencies are often concurrent with folic acid and biotin deficiencies in people whose hair has started to turn gray early. This connection leads many to ask: can vitamin B12 deficiency cause grey hair, and what can be done about it?

Quick Summary

Premature greying can be linked to a vitamin B12 deficiency, as low levels can impact melanin production, the pigment responsible for hair color. Other factors like genetics, stress, and diet also play a role, making diagnosis and treatment nuanced.

Key Points

B12 and Melanin Production: A deficiency in vitamin B12 can impair the function of melanocytes, the cells responsible for producing hair pigment, leading to premature greying.
Diagnosis is Key: Blood tests are necessary to confirm if a B12 deficiency is the underlying cause of grey hair, as genetics and other health issues are common culprits.
Reversibility is Conditional: While addressing a B12 deficiency may reverse hair color in some cases, particularly in children, it is not guaranteed and often depends on the root cause.
Dietary Sources are Crucial: Ensuring adequate B12 intake through animal products or fortified foods is important, especially for vegans and vegetarians who are at higher risk of deficiency.
Holistic Approach: Addressing premature greying requires a comprehensive strategy that considers genetics, stress, and other nutritional factors, not just B12.
Supplementation Requires Guidance: Taking B12 supplements should be done under a doctor's supervision, especially since it may only be effective if a deficiency is confirmed.
Hair Follicle Nourishment: B12 supports red blood cell formation, which delivers vital oxygen and nutrients to hair follicles, making it essential for healthy hair.

The Science Behind Hair Pigmentation and Vitamin B12

Hair color is determined by a pigment called melanin, which is produced by specialized cells within hair follicles known as melanocytes. As hair grows, melanin is integrated into the hair shaft, giving it its natural color. The greying process begins when melanin production decreases, either due to aging, genetic factors, or other influences.

Vitamin B12 plays a critical role in several bodily functions that indirectly affect hair health and pigmentation. It is essential for DNA synthesis and the formation of red blood cells. Red blood cells are responsible for carrying oxygen and nutrients to all cells in the body, including the melanocytes within hair follicles. When a vitamin B12 deficiency is present, the production of these healthy red blood cells is hampered, leading to under-nourished hair follicles. This can affect the optimal functioning of melanocytes, resulting in premature greying.

How B12 Deficiency Impacts Melanin Production

Impaired DNA Synthesis: B12 is a cofactor in the synthesis of DNA. A deficiency can affect the multiplication of cells, especially those with a high turnover rate, such as melanocytes. This disruption can directly impact melanin production.
Cellular Metabolism: Without sufficient B12, cell metabolism is compromised, which can specifically affect the hair follicles' ability to generate enough melanin.
Hypopigmentation: Cases have been reported, particularly in children, where B12 deficiency caused reversible hypopigmentation (lighter hair).

Other Factors Contributing to Premature Greying

While B12 deficiency is a known cause, it is rarely the only one. Premature greying is a multifaceted phenomenon influenced by a range of factors.

Genetics: This is the most common cause, with a strong family history being a significant predictor.
Oxidative Stress: Damage to melanocytes by free radicals, often caused by environmental factors like UV radiation, can accelerate the greying process.
Smoking: Research has found a strong link between smoking and premature greying.
Other Nutritional Deficiencies: Deficiencies in other micronutrients, such as copper, iron, zinc, and vitamin D, have also been associated with premature greying.
Thyroid Disorders: Conditions affecting the thyroid gland can influence hair pigmentation.
Stress: Chronic stress can damage the health of hair follicles, contributing to premature color loss.

Can B12 Supplementation Reverse Grey Hair?

If a B12 deficiency is the cause of premature greying, it is possible to see some color return with supplementation, but this is not guaranteed for everyone and depends on various factors.

Conditional Reversibility: Reversal is only likely if the B12 deficiency is the direct cause. If other factors like genetics are at play, supplementation is unlikely to have an effect.
Prevention vs. Reversal: In many cases, addressing the deficiency helps prevent further greying rather than fully reversing existing grey hair.
Medical Diagnosis: A proper diagnosis from a healthcare professional is essential. A blood test can confirm a B12 deficiency, and a doctor can rule out other potential causes before recommending treatment.
Supplementation Options: Treatment can involve oral supplements or B12 injections, especially in severe cases or for those with absorption issues.

A Comparative Look at Hair Greying Causes


Cause	Mechanism	Reversibility with B12	Diagnosis
B12 Deficiency	Impaired DNA synthesis and red blood cell production, affecting melanocyte function.	Possible, but not guaranteed and only if B12 is the root cause.	Blood test for serum B12 levels.
Genetics	Inherited traits determine the age at which melanocyte function declines.	No	Family history and age of onset.
Oxidative Stress	Free radical damage to melanocytes and hair follicles.	Unlikely with B12 alone; antioxidants may help.	Ruling out other factors.
Other Deficiencies	Lack of other essential nutrients (e.g., copper, iron, D) affects melanin production.	Variable, depends on which deficiency is addressed.	Blood tests for various micronutrients.
Smoking	Produces reactive oxygen species, damaging hair follicles.	No, but quitting can improve overall health.	Lifestyle history.

Dietary Sources of Vitamin B12

Ensuring adequate B12 intake is vital for hair and overall health. Since B12 is primarily found in animal products, diet is a key consideration, especially for vegetarians and vegans.

Rich Animal-Based Sources:

Meat (beef, liver, poultry)
Fish (salmon, tuna, trout)
Dairy products (milk, cheese, yogurt)
Eggs
Shellfish (clams, oysters)

Fortified and Plant-Based Options:

Fortified cereals
Nutritional yeast
Fortified plant-based milks (almond, soy, oat)

Vegans and vegetarians, due to their restricted diet, are at a higher risk of deficiency and should consider fortified foods or supplements to meet their B12 needs.

Conclusion

Can vitamin B12 deficiency cause grey hair? The answer is yes, a deficiency can be a contributing factor, particularly in cases of premature greying. However, the mechanism is complex, involving the impact of B12 on DNA synthesis and red blood cell production, which affects the health and pigment production of hair follicles. It is crucial to remember that B12 is not a magic bullet. Genetics and other factors often play a more dominant role in the greying process. If you are concerned about premature greying, a visit to a healthcare provider for a proper blood test is the most important step. A balanced diet and appropriate supplementation, if a deficiency is confirmed, can support hair health and potentially slow down the greying process. For more information on nutritional impacts on health, you can consult reliable resources like Healthline.

Frequently Asked Questions

No, premature greying is not always a sign of B12 deficiency. It can also be caused by genetics, stress, smoking, and deficiencies in other nutrients like copper and iron.

B12 is vital for red blood cell production, which transports oxygen to hair follicles. A deficiency can impact melanin-producing cells (melanocytes), leading to a loss of pigment.

Reversal of hair color is only possible if the deficiency is the underlying cause, and it is not guaranteed. Restoring B12 levels may, however, prevent further greying.

Rich sources include meat, fish (salmon, tuna), eggs, and dairy products. Fortified cereals, nutritional yeast, and plant-based milks are options for vegans and vegetarians.

Yes, since B12 is primarily found in animal products, those on strict plant-based diets are at a higher risk and often require fortified foods or supplements.

You should consult a healthcare professional and get a blood test first. Self-treating without a confirmed deficiency is not recommended and may not be effective.

The general recommendation for most adults is 2.4 mcg per day, though this can vary based on individual needs and dietary habits.

The most common cause of hair greying is genetics. If your family has a history of premature greying, it is likely that you will experience it too.