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Does Vitamin B12 Deficiency cause Hair Loss? Expert Review 2024
Dr. Umear Ahmad (GMC)
Medically reviewed by
Dr. Umear Ahmad (GMC)
Updated on May 16, 2024

Searching online for reasons why your hair is falling out, you may come across content stating that vitamin B12 deficiency causes hair loss. Since approximately 40% of the Western population has low or marginal amounts of this nutrient [1], that information may have you concerned. Could your hair loss be the result of a B12 deficiency?

Fortunately, it is unlikely that your hair thinning is caused by your B12 levels. While more research is needed on this subject, the studies that have been conducted so far have not revealed any causal relationship between this vitamin deficiency and excessive hair shedding [2].

While it is true that some patients with conditions such as alopecia areata or chronic telogen effluvium also present low levels of B12, no indication has been found that the vitamin deficiency has caused hair loss or made these conditions worse. Moreover, supplementation has not been found to improve the hair shedding [2].

Keep reading this article to find out more about:

  • What vitamin B12 deficiency is and how it can affect your health
  • The relationship between vitamin B12 and hair loss
  • Other vitamin and mineral deficiencies that can cause hair loss
  • The best ways to prevent and treat your hair loss
Table of Contents
About Vitamin B12 deficiency

About vitamin B12 deficiency

Vitamin B12 is a micronutrient commonly found in foods such as liver, fish, meat, eggs, cereals and dairy. However, if a deficiency is present, it can also be administered as a supplement [1]. The daily recommended dose of B12 for healthy adults is 2-4 micrograms per day, according to recent studies [2][3].

Since B12 has a low potential for toxicity, there is no upper threshold on how much of this vitamin it is safe to ingest – absorption rates decrease on their own when you have a sufficient amount in your system and it does not get stored over safe levels [2]. However, you can get too little B12, and many people do.

Vitamin B12 deficiency stems from a restrictive diet or absorption issues. If you eat enough foods that contain this vitamin and are still experiencing a B12 deficiency, your body may not be able to absorb the necessary amounts. This can happen due to conditions such as anaemia, gastrointestinal surgery or prolonged use of certain medications. Thus, the elderly, people with anaemia or gastrointestinal disorders and vegans are most predisposed to developing B12 deficiency [1].

Since vitamin B12 plays a significant role in keeping your red blood cells and nervous cells working in good order and contributes to the synthesis of your DNA, it is essential to get serious deficiencies treated [1][4]. So if you develop critically low levels of this vitamin, you may need to receive B12 injections or high-dose oral supplements.

symptoms of vitamin b12 deficiency

Symptoms of vitamin B12 deficiency:

The most common symptoms of vitamin B12 deficiency are as follows [5][1]:

  • Shortness of breath
  • Headaches
  • Digestive symptoms (e.g. indigestion, loss of appetite, diarrhoea)
  • Heart palpitations
  • Vision problems
  • Weakness and fatigue
  • A sore or red tongue (sometimes, mouth sores)
  • Cognitive issues (brain fog, memory issues)
  • Numbness and tingling in your limbs
Can B12 deficiency cause hair loss?

Can B12 deficiency cause hair loss?

At this time, there is insufficient evidence that B12 deficiency causes hair loss [2]. While few studies addressed the relationship between this micronutrient and hair shedding, most of them found no outstanding B12 deficiency in patients with different types of alopecia.

Three studies conducted in Turkey, on a total number of 147 patients with alopecia areata revealed no differences in B12 levels between the test group who experienced hair loss and the healthy control groups [6][7][2].

Similarly, a different study [8] conducted on 115 patients with chronic telogen effluvium showed that only 2.6% of them had a B12 deficiency and there was no evidence that it was contributing to their hair thinning. While a different article [9] performed on 100 Indian women with telogen effluvium, found a B12 deficiency in 36% of the participants, none of the two had control groups of people without hair loss to compare their vitamin levels.

Judging by the fact that B12 deficiency rates vary widely with the definition used for it (e.g. it can range between 3%-40% in older adults, depending on how it is calculated [1]), the two findings are not necessarily comparable.

Moreover, scientists who looked into the causes of trichodynia (burning scalp syndrome) in 91 patients with androgenetic alopecia and telogen effluvium found no significant differences in B12 levels between the test and control groups [10].

Finally, a small study performed on 11 women with female pattern baldness revealed no indication that lower levels of serum B12 increased hair loss [11].

Considering the current lack of substantial evidence to show that vitamin B12 contributes in any way to hair loss, supplementation is not recommended at this time for any type of alopecia or hair shedding [2].

premature hair graying

The effects of vitamin B12 on your hair

Researchers believe that this nutrient may play a role in hair follicle development and metabolism, alongside vitamin B9 (folate).  Since they are involved in red blood cell formation as well as the synthesis of DNA and proteins, having a B12 or folate deficit can slow down their production, impairing cell functions [2].

One in-vitro study suggests that B12 supplementation may be able to stimulate follicles for quicker hair growth after a hair transplant, which may lead to other applications for hair regeneration [12]. However, more research is needed to understand and confirm if B12 can encourage hair growth.

While lower levels of B12 have not been proven to cause hair loss, deficiency has been associated in relevant literature with premature hair greying [2][13]. A study conducted on 52 people under 20 years of age with premature greying revealed a B12 and folic acid deficiency in the test group which was not also reflected in the control group [14].

Will my hair grow back after a B12 deficiency?

Having a clinical deficiency of Vitamin B12 can cause anaemia, which is known to accelerate hair loss. However, while B12 supplementation can prevent further hair shedding, there is, unfortunately, no guarantee that your hair will grow back once you have corrected the deficiency.

If you are experiencing hair loss and have reasons to suspect nutritional deficiencies (e.g. a restrictive diet), it is best to get some blood tests, to rule out anaemia. Furthermore, seeing a trichologist from the first signs of hair thinning and balding can help you get a timely diagnosis of the condition which is making your hair thin. This way, you get treatment sooner and increase your chances of seeing hair regrowth.

What other nutrient deficiencies can cause hair loss

What other nutrient deficiencies can cause hair loss?

There are several nutrients the absence of which has been proven to cause hair loss. Here are some of the most common:

  • Iron – This is the most common nutritional deficiency in the world and it has been shown to contribute to telogen effluvium, although more evidence is needed to support this finding [15][16].
  • Zinc – This deficiency is known to contribute to alopecia, especially female/male pattern baldness and telogen effluvium. Supplementation has been shown to stimulate hair growth [17].
  • Vitamin B2 (Riboflavin) – while riboflavin deficiency is very rare, it has been associated with hair loss [18] However, studies have shown that supplementation does not result in hair regrowth [2].
  • Vitamin D for hair – While more research is needed, Vitamin D deficiency has been associated with alopecia areata and may play a role in telogen effluvium and androgenetic alopecia [2].
  • Vitamin E for hair – this vitamin protects your hair from oxidative stress [19], so a deficiency may lead to strand brittleness and hair breakage. Vitamin E deficiency has also been associated with alopecia areata, but study results are mixed [20][21]. However, excessive levels of vitamin E can also make your hair fall out [2].

Other conditions which cause hair loss

If your hair is falling out, your thinning may be caused by one of many conditions that cause hair loss. The most common of them are:

Androgenetic alopecia

Androgenetic alopecia

One of the most common types of alopecia, male/female pattern baldness is caused by age, and genetic and hormonal factors [22].

Male pattern hair loss often presents with the following symptoms:

Female pattern hair loss presents much differently from male pattern baldness. Symptoms include the following:

  • Diffuse hair loss
  • A widening of the midline parting
  • A Christmas tree sign around your midline parting

Telogen effluvium

telogen effluvium hair shedding

Telogen effluvium causes temporary hair loss and it is triggered by physical and emotional trauma. It normally resolves itself in under 6 months if the triggering event is removed [23].

Symptoms of telogen effluvium include the following:

  • Diffuse hair loss
  • Sometimes, a burning sensation on the scalp

Alopecia areata

Alopecia areata on the scalp

This autoimmune condition can take several forms. Rarer ones include ophiasis alopecia, alopecia totalis and alopecia universalis [24].

Alopecia areata presents with the following symptoms:

  • Round, smooth bald patches (patchy hair loss)
  • Smaller, broken hairs that resemble exclamation marks
  • Yellow or dark dots on your scalp
  • Sometimes, hair loss in your eyebrows or beard

Symptoms of ophiasis alopecia include:

  • A smooth, wavy bald band, usually at the back of the head

Symptoms of alopecia totalis include:

  • Complete hair loss on your head

Symptoms of alopecia universalis include:

  • Complete hair loss on your entire body

Traction alopecia

traction alopecia

Wearing tight hairstyles, such as braids or ponytails can cause hair loss. This type of temporary hair shedding is called traction alopecia and often resolves itself once you stop putting pressure on your hair roots [25].

  • Hair loss around the temples and fringe area (or any area where hair is repeatedly pulled)
  • Bumps on the skin
  • Tenderness, tingling or irritation in the affected area

Common scalp problems

scalp psoriasis

Conditions such as seborrheic dermatitis, eczema, scalp psoriasis or scalp folliculitis can lead to hair loss in the affected areas. Fortunately, treating them often results in healthy hair growth.

Depending on the condition, the symptoms may vary, but they can often include:

  • Dry, cracked skin
  • White, silver or yellow flaking
  • Inflammation in the affected area
  • Itchiness, pain, burning or tenderness on the scalp
  • Pustules around your hair follicles

Lifestyle-induced hair damage

Avoid frequent heat styling to improve hair health

Excessive use of heat-styling or harsh chemicals such as bleach or hair dye can cause hair loss. Smoking and vaping can cause hair loss as well and excessive exposure to sunlight is not good for your hair health, as it can lead to oxidative damage.

The most common symptoms of lifestyle-induced hair damage are:

  • Dry, brittle hair that breaks easily
  • Flat, lacklustre tresses
  • Rough, frizzy locks that are hard to style
  • Split ends

Are you concerned about hair loss?

Are you wondering whether your hair is thinning or you are being paranoid? While some hair loss is normal in the shower, if you are routinely shedding more than 50-100 strands each day, your concern may be well founded. That is why the best course of action is to book a consultation with a trichologist.

They will perform a careful examination of your hair and scalp and accurately determine your diagnosis. Then, they will recommend the most appropriate personalised treatment for your condition. This may include efficient medications (such as Minoxidil or Finasteride), therapies (e.g. derma rolling for hair growth or low-level light therapy for hair growth) or surgical options, such as a hair transplant.

Whatever their recommended hair loss treatment might be, you can rest assured that your hair is in the best hands and that they will be doing everything in their power to help you regrow fuller, healthier locks.

Does Vitamin B12 Deficiency cause Hair Loss? Expert Review 2024, Wimpole Clinic

  1. Vitamin B12
  2. The Role of Vitamins and Minerals in Hair Loss: A Review
  3. The Revised D-A-CH-Reference Values for the Intake of Vitamin B12: Prevention of Deficiency and Beyond
  4. The role of vitamin B12 in DNA modulation mechanisms
  5. Symptoms Vitamin B12 or folate deficiency anaemia
  6. Serum vitamin B12, folate, ferritin, and iron levels in Turkish patients with alopecia areata
  7. Serum holotranscobalamine, vitamin B12, folic acid and homocysteine levels in alopecia areata patients
  8. Vitamin and Mineral Deficiencies in Patients With Telogen Effluvium: A Retrospective Cross-Sectional Study.
  9. Evaluation of serum ferritin, vitamin B12 and vitamin D levels as biochemical markers of chronic telogen effluvium in women.
  10. The role of psychological factors and serum zinc, folate and vitamin B12 levels in the aetiology of trichodynia: a case–control study
  11. Reduced serum vitamin B12 levels during oral cyproterone‐acetate and ethinyl‐oestradiol therapy in women with diffuse androgen‐dependent alopecia
  12. Vitamin B12 Activates the Wnt-Pathway in Human Hair Follicle Cells by Induction of -Catenin and Inhibition of Glycogensynthase Kinase-3 Transcription
  13. Relationship between diet, atopy, family history, and premature hair graying
  14. Prospective Analytical Controlled Study Evaluating Serum Biotin, Vitamin B12, and Folic Acid in Patients with Premature Canities
  15. The diagnosis and treatment of iron deficiency and its potential relationship to hair loss
  16. Diffuse hair loss in an adult female: Approach to diagnosis and management
  17. Analysis of Serum Zinc and Copper Concentrations in Hair Loss
  18. Encyclopedia of Dietary Supplements
  19. Antioxidants and lipid peroxidation status in the blood of patients with alopecia
  20. Oxidative stress and alopecia areata
  21. The Antioxidant Role of Paraoxonase 1 and Vitamin E in Three Autoimmune Diseases
  22. Androgenetic alopecia: An update
  23. Telogen Effluvium: A Review of the Literature
  24. Alopecia Areata: Review of Epidemiology, Clinical Features, Pathogenesis, and New Treatment Options
  25. Traction Alopecia
Dr. Umear Ahmad (GMC)
Medically reviewed by Dr. Umear Ahmad (GMC)Updated on May 16, 2024
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