Can B12 deficiency cause hair loss?

5th April 2025

For many people, thinning hair or hair loss can feel like an inevitable part of ageing. While androgenetic alopecia (genetic hair loss) is often a common cause, lifestyle issues and nutritional deficiencies can sometimes be overlooked.

In particular, vitamin B12 deficiency may play a role in hair loss. In this blog, we’ll explore the role of vitamin B12 in hair health, how B12 deficiency can cause hair loss, and what steps you can take to restore your B12 levels and promote healthier hair growth.

Understanding vitamin B12

Vitamin B12 is a vital vitamin that plays a key role in numerous bodily functions, including red blood cell production, nerve functioning, and DNA synthesis (the production of DNA). The body doesn’t produce B12 on its own, so it must be obtained through diet or supplements.

The NHS has information about good sources of B12.

How does B12 deficiency cause hair loss?

There are several ways that B12 deficiency may impact the hair:

  • Reduced oxygen and nutrient delivery: Our body is full of cells which are continually dividing to make new cells. Hair follicles are among the most rapidly dividing cells in the body. To maintain their growth cycle, they require a steady supply of nutrients and oxygen – both of which depend on red blood cells. B12 plays a critical role in producing healthy red blood cells. If you’re deficient in B12, the reduced red blood cell count can limit oxygen delivery to your scalp and hair follicles.
  • Reduced cell division: Hair growth depends on the rapid division of cells in the scalp. A lack of B12 can disrupt this process and impact how well the hair grows.
  • Impaired follicle functioning: B12 helps to metabolise proteins and other nutrients that are key for healthy hair follicles and continuous hair growth. Without enough B12, hair follicles can struggle to work effectively.

Although we know that B12 plays an important role in many body functions, and in theory, hair growth, scientific studies are limited. So while B12 deficiency may be linked to hair loss, it’s important to see a professional if you are experiencing any hair-related symptoms to explore if anything else is also playing a part.

What are the symptoms of a B12 deficiency?

When it comes to hair loss, a lack of B12 could lead to:

  • Hair shedding
  • Thinning hair
  • Weak, brittle hair that breaks easily
  • Dull hair
  • Changes to hair texture

If a B12 deficiency is causing your hair loss, you’ll likely experience some other symptoms too, including fatigue and weakness, shortness of breath, headaches and palpitations.

Learn more about symptoms of a B12 deficiency on the NHS website. 

If you’re experiencing several symptoms of a B12 deficiency, consult a healthcare provider and request a blood test to check your B12 levels. It’s important not to self-diagnose – symptoms of a B12 deficiency can be quite general, so it’s good to get a comprehensive medical assessment to rule out other conditions and accurately diagnose a B12 deficiency.

Treatment for a B12 deficiency

The good news is that in most cases, hair loss caused by a B12 deficiency can be reversed. It usually requires a broad approach and might vary depending on individual needs. Some B12 treatment options include:

  • Oral supplements: to help keep sufficient B12 levels in those with a mild deficiency
  • B12 injections: for more moderate to severe cases of B12 deficiency
  • Diet changes: including eating more B12-rich foods like eggs, milk, meat, nutritional yeast, and foods fortified with B12 (which are often helpful for people who want to eat meat and/or dairy alternatives)

It’s important to follow the advice from a healthcare professional to make sure that treatment for B12 deficiency is tailored to your unique requirements.

Although hair loss caused by B12 deficiency can usually be reversed, recovery isn’t instant. Hair grows slowly (about half an inch per month), so it may take a while to see significant improvements.

Seeing a hair specialist

Still struggling with hair loss after treatments for a B12 deficiency? B12 deficiency may not be the only cause of your hair loss – it may be that there are other factors also at play.

Hair loss can be caused by a wide range of factors including genetics, stress, hormones, medical conditions and treatments, or other lifestyle factors.

At The Maitland Clinic, we take a holistic approach to diagnosing hair loss, considering a range of factors like your medical history, lifestyle, diet, and genetics. We also conduct a thorough scalp examination using advanced technology, and chat to you about your hair history, concerns and goals.

All of this helps us to get an accurate diagnosis and establish the most effective treatment plan for your needs.

Get in touch with our expert team

We understand how upsetting it can be to go through hair loss of any kind. Whether it’s a B12 deficiency causing hair loss, or there are other factors involved, our dedicated team of hair loss specialists can help identify the underlying cause and create a personalised treatment plan tailored to your needs.

To learn more about how we can help, arrange a consultation using our online form.