Does B12 Deficiency Cause Hair Breakage?

October 23, 2025 •

4 min read

According to recent studies, low levels of certain vitamins are more common in people experiencing hair loss. This raises the question: does B12 deficiency cause hair breakage? While not the sole cause, a lack of vitamin B12 can significantly impact hair strength, leading to brittle, fragile strands.

Quick Summary

Explore the link between low vitamin B12 and fragile hair. Understand how deficiency affects hair follicle function and nutrient delivery, resulting in increased shedding and brittleness.

Key Points

Indirect Cause: B12 deficiency can lead to hair breakage by impairing red blood cell production, which reduces oxygen and nutrient supply to hair follicles.
Anemia Link: Low B12 levels can cause megaloblastic anemia, further weakening hair strands and increasing the likelihood of shedding and breakage.
Multiple Factors: While B12 is a contributor, external factors like heat styling, chemical treatments, and aggressive brushing are also major causes of hair breakage.
Other Symptoms: Hair problems from B12 deficiency are often accompanied by other symptoms like fatigue, tingling sensations, and mood changes.
Confirmation is Key: A proper diagnosis via a blood test from a healthcare professional is necessary to confirm a B12 deficiency as the cause.

The Role of Vitamin B12 in Hair Health

Vitamin B12 is a powerhouse nutrient, essential for numerous bodily functions, including the production of red blood cells. Red blood cells are crucial because they act as delivery vehicles, transporting oxygen and vital nutrients throughout the body, including to the hair follicles in your scalp. Without a steady and sufficient supply of oxygen and nutrients, hair follicles cannot perform their function of growing strong, healthy hair. This impairs the cell division necessary for hair growth, leading to weakened follicles and brittle hair that is more prone to breakage.

B12, Anemia, and Hair Strength

A deficiency in vitamin B12 can lead to a condition known as megaloblastic anemia, where the body produces fewer and larger than normal red blood cells. This condition further limits the oxygen and nutrient supply to the hair follicles, exacerbating hair thinning and excessive shedding. Hair, which is primarily composed of the protein keratin, requires an ample supply of amino acids and nutrients to maintain its structural integrity. When this supply is compromised due to anemia caused by B12 deficiency, the resulting hair strands are weaker, drier, and more susceptible to damage and breakage.

Other Symptoms of B12 Deficiency

Hair-related issues are often not the only sign of low B12 levels. The body requires this nutrient for nerve function, DNA synthesis, and cellular metabolism. As a result, a deficiency often presents with a range of symptoms, including:

Extreme fatigue and low energy
Numbness or tingling sensations, often in the hands and feet
Changes in mood, such as depression or irritability
A swollen, inflamed, or sore tongue
Shortness of breath or heart palpitations
Memory loss and difficulty concentrating

B12 Deficiency vs. Other Causes of Hair Breakage

While a B12 deficiency can be a contributing factor, hair breakage is often the result of multiple issues, both internal and external. It is crucial to understand all potential causes to identify the root of your hair problems and pursue the most effective treatment.

Common Causes of Hair Damage and Breakage

Over-styling and heat damage: Frequent use of flat irons, curling wands, and blow dryers can strip hair of its natural moisture, leaving it brittle.
Chemical treatments: Bleaching, perming, and chemical straightening alter the hair's structure and can severely weaken it.
Tight hairstyles: Constantly wearing tight ponytails or braids can put stress on the hair shaft, leading to breakage.
Aggressive brushing: Rough brushing, especially on wet hair, can cause mechanical damage and snapping.
Other nutritional deficiencies: Low levels of iron, zinc, and other vitamins can also contribute to weak, brittle hair.
Stress: Chronic stress can disrupt the hair growth cycle, leading to increased shedding, known as telogen effluvium.

How to Address B12-Related Hair Problems

If you suspect a vitamin B12 deficiency, the first step is to consult a healthcare professional. A simple blood test can confirm your vitamin B12 levels and help determine the best course of action.

Diagnosis and Treatment Table


Action	Purpose	Treatment Options
Blood Test	To confirm a B12 deficiency.	A definitive way to check serum B12 levels.
Dietary Changes	To increase B12 intake naturally.	Increase consumption of B12-rich foods like meat, fish, eggs, and dairy. Vegans and vegetarians can use fortified foods or nutritional yeast.
Oral Supplements	To boost levels in mild to moderate cases.	Over-the-counter B12 pills can help maintain adequate levels.
B12 Injections	For severe deficiency or malabsorption.	Administered by a doctor for rapid restoration of B12 levels.
Medical Management	To treat underlying causes of malabsorption.	Manage conditions like pernicious anemia, Crohn's, or celiac disease that may prevent proper B12 absorption.

Conclusion: Can B12 Deficiency Cause Hair Breakage?

In conclusion, a vitamin B12 deficiency can indeed lead to symptoms associated with hair breakage, such as weakness, dryness, and excessive shedding. The mechanism is linked to its crucial role in red blood cell production, which is responsible for oxygen and nutrient delivery to the hair follicles. However, it's important to remember that hair breakage is often a complex issue with multiple potential causes, including environmental factors, styling habits, and other nutritional shortfalls. Addressing an underlying B12 deficiency through diet or supplementation can help improve hair health and reduce breakage, but for some, additional interventions or treatment for other causes may be necessary. Consulting a healthcare provider for a proper diagnosis is the most effective approach to identifying and treating the root cause of your hair concerns.

For more detailed information on vitamins and their effects on hair loss, including the roles of vitamin D, C, and iron, refer to reputable sources like the article from Harvard Health: Vitamins, minerals, and hair loss: Is there a connection?.

Frequently Asked Questions

A B12 deficiency impairs the production of red blood cells, which carry essential oxygen and nutrients to your hair follicles. With insufficient nourishment, the hair produced is weaker and drier, making it brittle and prone to breaking.

Yes, in many cases, hair loss and breakage caused by a B12 deficiency can be reversed with proper treatment, such as supplements, diet changes, or injections. However, hair grows slowly, so visible improvements may take several months.

To restore B12 levels, incorporate foods like meat, fish (salmon, tuna), eggs, and dairy products into your diet. For vegans and vegetarians, fortified cereals and nutritional yeast are excellent sources.

It is essential to consult a healthcare provider for a blood test before starting supplements. If a deficiency is confirmed, supplementation can be effective. Taking B12 when your levels are already normal is unlikely to improve hair health.

Yes, other deficiencies can also cause hair breakage and loss. These include low levels of iron, zinc, and vitamin D, as these nutrients are all vital for healthy hair production.

Consider your other symptoms. If your hair breakage is accompanied by fatigue, weakness, or nerve issues, a B12 deficiency is more likely. However, only a medical professional can provide a definitive diagnosis.

A vitamin B12 deficiency is linked to both hair breakage and increased hair shedding (hair loss). The same underlying mechanisms of poor nutrient supply to hair follicles can cause strands to become fragile and also trigger excessive shedding.