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Does Vitamin B12 Deficiency Cause Hair Loss or Is It a Myth?
Dr. Umear Ahmad (GMC)
Medically reviewed by
Dr. Umear Ahmad (GMC)
Updated on August 14, 2024

You may have heard that vitamin B12 deficiency causes hair loss and it may have made you wonder if that is the reason why your hair is falling out. Since approximately 40% of the Western population has low or marginal amounts of this nutrient [2], it is normal to be concerned. Could your hair loss be the result of a B12 deficiency?

Fortunately, it is unlikely that your hair is falling out on account of 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 [3]. 

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 [3].

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

The link between vitamin B12 and hair loss

At this time, there is insufficient evidence that B12 deficiency causes hair loss [3]. 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 [7][8][2]. 

Similarly, a different study [9] 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 condition. 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 [2]), 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 [11]. 

Finally, a small study performed on 11 women with female pattern baldness revealed no indication that lower levels of serum B12 increased hair loss [12].

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 [3].

Vitamin B12 supplements

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 [2]. The daily recommended dose of B12 for healthy adults is 2-4 micrograms per day, according to recent studies [3][4].

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 [3]. 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 [2].

Since vitamin B12 plays a significant role in keeping your blood and nervous cells working in good order and contributes to the synthesis of your DNA, it is essential to get serious deficiencies treated [2][5]. So if you develop critically low levels of this vitamin, you may need to receive B12 injections or high-dose oral supplements.

Woman with symptoms of vitamin B12 deficiency

Symptoms of vitamin B12 deficiency:

If you have clinical vitamin B12 deficiency, you may experience a range of symptoms, from mild to severe. Here are some of the common ones that you might encounter [6][2]:

  • 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

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 the synthesis of DNA and proteins, having a B12 or folate deficiency can slow down their production, impairing cell functions [3]. 

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 [13]. However, more research is needed to understand and confirm this effect. 

While lower levels of B12 have not been proven to cause hair loss, deficiency has been associated in relevant literature with premature hair greying [3][14]. 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 [15]. 

If you are worried about premature greying, find out more if it is possible to reverse grey hair.

Man hoping if his hair will grow back after a B12 deficiency

Will my hair grow back if I take B12 supplements?

While B12 deficiency alone shouldn’t cause hair loss, having a clinical deficiency of this nutrient can cause anaemia, which is known to accelerate hair shedding. However, while B12 supplementation can prevent further hair loss, 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.

Supplements for nutrient deficiencies that 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 [16][17]. Learn more about how iron deficiency anaemia affects hair.
  • Zinc – This deficiency is known to contribute to alopecia, especially female/male pattern baldness and telogen effluvium. Supplementation has been shown to stimulate hair regrowth [18]. 
  • Vitamin B2 (Riboflavin) – while riboflavin deficiency is very rare, it has been associated with hair loss [19] However, studies have shown that supplementation does not result in hair regrowth [3] 
  • 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 [3].
  • Vitamin E for hair – this vitamin protects your hair from oxidative stress [20], 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 [21][22]. However, excessive levels of vitamin E can also make your hair fall out [3].

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:

Man with 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 [23]. It occurs when your body starts producing excessive amounts of a male hormone called dihydrotestosterone (DHT). DHT binds to androgen receptors in your hair follicles, which makes them become smaller and impairs their hair-producing function. 

Main symptoms:

Male pattern baldness manifests differently from female pattern baldness. Thus, in men, the first signs of androgenetic alopecia usually include an uneven or receding hairline and temple hair loss. As the alopecia progresses, they may develop a bald spot on the crown.


Women are often spared the M-shaped hairline. However, they experience a progressive increase in width of their normal hair parting, which may also form a Christmas tree pattern. They are also likely to present diffuse hair thinning which can be expected to advance if left untreated.

Treatments:

Minoxidil is generally effective in treating androgenetic alopecia in both genders, as it improves blood flow to your hair follicles. Men are also frequently recommended Finasteride or Dutasteride, which lower the levels of DHT in your blood. However, neither of these medications are recommended to premenopausal women, as they can produce birth defects and hormonal imbalances.

Woman with telogen effluvium

Telogen effluvium

This condition 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 [24].

Main symptoms:

The chief complaint of patients with telogen effluvium is diffuse hair loss all over their scalp. They normally don’t have any other symptoms. However, in some cases, they may also experience trichodynia (a burning sensation on their scalp). 

Treatments:

Normally, this condition should resolve itself without treatment in about 3 months after the end of the stressful event. However, should it become chronic, Minoxidil could help you achieve hair regrowth. 

Patient with alopecia areata

Alopecia areata

This type of alopecia is autoimmune, which means your white blood cells are attacking your hair follicles. While it is rather rare, affecting approximately 2% of the worldwide population, this condition can take several forms. Rarer ones include ophiasis alopecia and alopecia totalis [25].

Main symptoms:

The most common presentation of alopecia areata is with smooth, round bald patches on your scalp. You may also find broken hairs shaped like exclamation marks and your scalp may also show yellow or black dots. This condition can sometimes also affect the eyebrows and beard. And in rare cases, it can lead to complete hair loss on your scalp (alopecia totalis) or your entire body (alopecia universalis).

Treatments:

Milder forms of alopecia areata show spontaneous hair regrowth within a year of onset (though you can often expect further flare-ups over time). However, more severe ones can require treatment with steroid creams or intralesional steroid injections to reduce inflammation and achieve hair regrowth (although hair loss can sometimes be permanent). 

Woman with traction alopecia
[27]

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 [26].

Main symptoms:

If you have developed traction alopecia, you may experience hair loss around the temples and fringe area. Your scalp may also look bumpy or irritated and you may be feeling tenderness, pain or tingling in the affected area. 

Treatments:

Normally, no treatment is needed for this condition. Your hair will start to grow back once you stop tying it tightly and your follicles get a chance to heal. However, if the problem persists or your traction alopecia is advanced, your hair doctor may recommend topical Minoxidil or PRP hair treatments or red light therapy for hair growth.

Woman with scalp psoriasis
[28]

Common scalp problems

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 hair regrowth.

Main symptoms:

Each scalp problem has its own characteristic symptoms. However, most manifest with irritation, redness and inflammation of the scalp. You may also notice silver or greasy, yellow flaking, plaques, pustules or lesions on your scalp. These symptoms can lead to scalp itchiness, tenderness and pain and sometimes you may also feel a burning or tingling sensation.   

Treatments:

Treatment may vary for each type of scalp problem. Yeast infections on the scalp (e.g. dandruff, seborrheic dermatitis) can usually be treated with medicated shampoo such as Nizoral. Bacterial infections (such as scalp folliculitis) which do not improve with home care may require antibiotics. And inflammatory conditions such as scalp psoriasis or eczema may be soothed with topical or injectable corticosteroids.  

Woman with lifestyle-induced hair damage

Lifestyle-induced hair damage

Excessive heat styling can lead to hair loss, as can using harsh chemicals, such as bleach, hair dye and even shampoos that contain sodium lauryl/laureth. A restrictive diet can also deprive your hair of the necessary nutrients. And stress and anxiety can cause hair loss as well, as they can trigger telogen effluvium. 

Main symptoms:

In many cases, poor styling choices, an improper diet or a stressful lifestyle can cause dry, brittle hair that breaks off easily. Your strands may start looking flat, dull and lacklustre and may develop split ends. Moreover, styling your hair can become more difficult, as it can become frizzier and rougher. And if you are under a lot of pressure, you may develop diffuse hair thinning.

Treatments:

If you are looking to improve your hair health after it suffered lifestyle-induced damage, you just need to make a few changes to the way you live and style your hair. Reducing heat styling and choosing gentle hair products are a great first step. Then, make sure to eat a well-balanced diet for healthy hair and to lower the stress levels in your life. Reducing smoking and keeping your hair out of the sun can also prevent or reduce hair loss.

Woman concerned about hair loss seeing hair doctor

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 recommendation 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 or Is It a Myth?, Wimpole Clinic

Frequently asked questions

The foods with the highest Vitamin B12 content are liver, clams, oysters, fish, beef, cheese and eggs [2][29]. However, if you are eating a balanced diet and still find you have a vitamin B12 deficiency, you may want to talk to your healthcare provider. That is because you may be experiencing a condition that prevents you from absorbing this nutrient adequately.

As long as you are getting the daily recommended value of vitamin B12 (2.4 micrograms for adults), you should absorb enough of this nutrient. However, while it may have a role in healthy hair production, there is no evidence that supplementing vitamin B12 will make your   hair grow thicker or faster.

No, vitamin B12 is normally safe even in high doses and excessive intake should not make your hair fall out. Since it has a low potential for toxicity, you should be experiencing no significant health side effects from overdosing on B12. That is because your body does not store too much of this nutrient, it simply eliminates the excess.

Yes, it is safe to take vitamin B12 alongside other hair vitamins. But if you are taking a vitamin complex, it would be a good idea to check if it already contains this nutrient before taking additional B12. While taking a higher dose won’t likely harm you, it is unnecessary, as your body will not be able to use it.

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