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Do Vitamins Really Promote Hair Growth? A Systematic Review Of The Science
Dr. Michael May (FRCS)
Medically reviewed by
Dr. Michael May (FRCS)
Updated on January 27, 2023

Contents:

Introduction

The hair supplement industry is expected to boom over the next 10 years, reaching a predicted value of $2.86 billion in 2031. It’s estimated that 58% of adults in the US and 38% in the UK take dietary supplements. But while mineral supplements and vitamins for hair growth are an increasingly popular choice of hair loss remedy, there’s actually very little evidence they work.

We’ve analysed 30 major reputable research studies into the relationship between hair and nutritional supplements to establish whether vitamin supplements can actually help with hair loss.

There are apparent links between vitamin deficiencies and some types of hair loss, including male pattern baldness, female pattern hair loss, telogen effluvium, and alopecia areata. But despite the popularity of hair supplements, research shows that vitamin supplements have a limited impact on hair growth and hair loss prevention.
In this article, you’ll find out if vitamin supplements can truly tackle hair loss — or if it’s better to seek more established hair loss medications.

What are vitamins?

Vitamins are essential micronutrients that play an essential role in maintaining good health. They’re vital for normal body function — from an efficient immune system to a healthy brain and nervous system. A total lack of any one vitamin can be deadly.

Most people get the vitamins they need from their diet. But if you don’t eat a balanced diet, you may not be getting enough vitamins. That’s why many people turn to vitamin supplements.

Supplements can be helpful. The NHS recommends that people living in the UK take a vitamin D supplement in winter, due to lack of sunlight. Folic acid (vitamin B12) supplements are also recommended for pregnant women.

But can vitamin supplements help hair loss, or is this a myth? To find out, it’s useful to know a little more about the history of vitamin supplement popularity.

Vitamin supplements were first introduced in the early 20th century as a way of fighting diseases borne out of vitamin deficiency. Common diseases at the time included scurvy, rickets, and nerve damage. A 1941 report found that a third of the US population were living on or below the subsistence level during World War 2, leading to poor nutrition [1]. This led to the first set of government-sponsored recommended daily allowances: six vitamins and two minerals.

But now, in the developed world, at least, vitamin deficiencies — and the ensuing diseases — are rare. So why is the vitamin supplement market still flourishing?

The idea that taking a vitamin pill or supplement can improve your health (and prevent baldness) has become increasingly appealing as people become more health-conscious. This, along with lobbying and lack of regulation in the vitamin supplement sector, has led to a boom in the supplement market [2]. Herbalife, a multi-level marketing company that sells supplements, spent almost $600,000 lobbying for dietary supplements in 2018 alone [3].

That’s not to say there’s no link between vitamins and hair growth. As we’ll demonstrate, some supplements have been shown to have a positive effect on patient hair. But it’s important to understand that while some vitamin supplements are useful in certain scenarios, much of their popularity is down to successful marketing campaigns, rather than scientific evidence.

Sudden or significant dietary changes can disrupt the hair growth cycle. That’s why extreme low-calorie diets and eating disorders like anorexia are often linked with hair shedding [4]. The exact mechanism that causes hair loss when you stop or reduce food intake is still being established — but nutritional deficiencies are likely to play a big part.

We’ve analysed data from 21 studies to establish whether each of these hypothetical hair growth vitamins actually impacts hair loss.

While there does seem to be a connection between vitamin deficiency and hair loss, there’s little evidence that vitamin supplements can actually help hair regrow. Here are our key findings:

  • 4 major types of hair loss may be linked with vitamin deficiency: male pattern baldness, female pattern baldness, telogen effluvium, and alopecia areata
  • Low levels of vitamins A and D — as well as zinc, iron, folate, and vitamin E — may have a significant impact on development of alopecia areata
  • Iron and zinc may contribute to development of pattern hair loss in all genders — but while female pattern hair loss is also associated with low levels of vitamin D, male pattern baldness is more closely linked with lack of biotin
  • The association between vitamins and hair growth is chronically understudied, leading to lack of accurate information about the effects of hair growth supplements
  • We’ve analysed each hair loss condition in greater detail to establish the impact of low micronutrient levels in the development of each major hair loss condition.

Important distinction between vitamin deficiency and inadequacy

Nutritional deficiencies are often confused with nutritional inadequacies.

Nutritional deficiencies occur when a person has extremely low vitamin and/or mineral levels. These levels are so low that they trigger observable clinical symptoms. For example, a vitamin D deficiency may cause bone pain and even fractures, while a vitamin A deficiency can lead to night blindness and other vision problems [5-6].

Those with nutritional inadequacies have low levels of vitamins and minerals, but they still have enough stores to prevent significant symptoms like those described above.

Vitamin companies and online articles tout the benefits of tackling nutritional deficiencies — but most consumers don’t realise that deficiencies are extremely rare in the developed world.

“The popular belief is that a supplement is going to be helpful for promoting health,” says Fang Fang Zhang, a professor at Tufts University’s Friedman School of Nutrition Science and Policy [7].

But if you’re already healthy, most supplements may not do much to improve your health. “There’s no clear evidence to suggest benefits of dietary supplement use for many popular or common health outcomes,” says Zhang.

What happens if you take too many vitamin supplements?

Taking vitamin supplements you don’t need can be inconsequential, or in some cases even harmful.

According to a US-based study that lasted for 10 years, an average of 23,000 emergency department visits per year were caused by negative effects of supplements [8].

Fat-soluble vitamins, such as vitamin A, D, E and K, can be stored in the body’s fat tissue. Taking too many fat-soluble vitamins can lead to toxicity if taken in large amounts over time. It can cause symptoms such as nausea, vomiting, headaches, skin problems and even serious health issues like liver damage.

How many people have micronutrient inadequacies?

This table shows the percentage of the US population over the age of 4 to have micronutrient inadequacies, especially vitamins and minerals commonly associated with hair loss [9]:

Micronutrient % < EAR (Estimated Average Requirement)
Vitamin D 94.3
Vitamin E 88.5
Vitamin A 43.0
Vitamin C 38.9
Zinc 11.7
Folate 9.5
Iron 7.4
Vitamin B12 2.5
Riboflavin 2.1
Niacin 1.1
Selenium 0.3

In the US (and most Western countries), nutritional deficiencies are rare — but inadequacies are extremely common.

The published studies we reviewed don’t compare micronutrient levels in deficient or inadequate patients with healthy patients.

Vitamin inadequacies are widespread in people both with and without hair loss, so it’s essential to know how these groups compare to discover the true relationship between vitamins and hair loss.

By analysing data that compares inadequate/deficient groups with healthy patients, we reveal the real hair-related risks of low vitamin levels.

Vitamins For Alopecia Areata

Alopecia areata is an autoimmune hair loss condition that’s notoriously difficult to treat, thanks to its high rate of spontaneous recovery and the disputed cause of the condition [10]. But it’s the most widely researched condition in relation to the effect of micronutrients, perhaps because the cause is still unclear.

Vitamin deficiency may play a significant role in the development of alopecia areata. Multiple studies indicate a link between vitamin D deficiency and development of alopecia areata. Immune cells in autoimmune diseases are known to respond well to vitamin D treatment, so it’s unsurprising that a lack of vitamin D may cause or worsen an autoimmune condition like alopecia areata [11].

A diagram showing micronutrient deficiencies in alopecia areata patients
[12-23]
Lack of vitamin A, iron, vitamin E, folate, and zinc may also contribute to alopecia areata development. But alopecia areata also appears in people with normal levels of these micronutrients — so while micronutrient deficiency may be a contributing factor, it’s unlikely to be the sole cause of this condition.

That said, it’s important to note the small sample sizes involved in this research. These vitamin D studies investigated deficiency levels in 60, 90, and 144 patients respectively, so these conclusions can’t necessarily be applied to all or even most alopecia areata sufferers [13-15].

Vitamins For Male Pattern Baldness

Genetics and age are the main causes of male pattern hair loss [25]. Perhaps because of this, the impact of nutritional deficiencies has been studied less extensively than in other hair loss conditions. The study samples are also small, with no study analysing more than 84 male androgenetic alopecia patients. Despite this, some studies have found statistically significant links between hair loss and low levels of certain vitamins and minerals.

Zinc and iron deficiencies appear to have ties with male pattern hair loss, though the evidence is far from conclusive [26]. Lack of biotin may also play a part in the development of male pattern baldness [24].

To date, Finasteride is the best non-surgical treatment for male pattern baldness.

Vitamins For Female Pattern Baldness

A graph showing micronutrient deficiencies in female pattern baldness patients
[16, 27-29]
Like male pattern baldness, female pattern hair loss is mainly caused by genetics, hormones, and age. Again, sample sizes are small — but female pattern hair loss has been conclusively linked with vitamin D deficiency.

This doesn’t appear to also affect male pattern baldness. So vitamin D may impact hair growth mechanisms unrelated to androgens (male sex hormones that react with genes to cause hair loss) [28]. While vitamin D doesn’t cause female pattern hair loss, it may worsen or speed up development of the condition. Zinc and iron deficiencies may also be linked with female pattern hair loss [26].

In contrast, Minoxidil is a proven treatment for female pattern baldness. Diagnosing women’s hair loss can be difficult, so hair loss blood tests are often needed to diagnose thinning hair in women.

Vitamins For Telogen Effluvium

A diagram showing micronutrient deficiencies in telogen effluvium patients
[16, 27, 30-33]

Telogen effluvium is a type of diffuse thinning that spreads across the scalp. This type of hair loss is usually caused by stress, emotional shock or trauma — but research suggests nutritional deficiency may also play a role.

Iron deficiency is the most widely studied micronutrient deficiency in relation to telogen effluvium. It seems to have substantial links to this type of hair loss, with multiple studies revealing low iron levels in telogen effluvium patients (though each study has a relatively small sample size, ranging from 60 to 120). This is particularly the case in female patients, who are generally more likely to experience iron deficiency [34]. Find out more about the impact of iron on hair texture.

Interestingly, one study found that vitamin D levels were higher in telogen effluvium patients. This may be due to the high sun exposure of the study participants, who were based in Turkey. Excessive sun exposure can cause hair shedding, while also stimulating vitamin D production in the body.

How conclusive is the data on hair loss and vitamin deficiency?

This data is taken from all available reputable research studies from major publications up to June 2022 — 21 studies in total. We’ve compared and analysed their results to establish clear connections between vitamins and hair loss where they arise.

But this field is understudied. Because vitamin and mineral supplements aren’t required to undergo the rigorous testing of other medicines, there’s less research into their effectiveness, especially related to cosmetic conditions like hair loss.

Each of the study populations is also limited in size, with the number of participants ranging from 30 to 342. The average number of participants across all studies is 101. Millions of people experience hair loss — so the findings of these small-scale studies can’t be extrapolated to all alopecia patients [25, 35].

Certain hair loss conditions (alopecia areata, telogen effluvium) have also been studied in far more depth than others (pattern hair loss), making their data somewhat more reliable.

It’s also important to be wary of extrapolating data across regions. Factors like climate and wealth may impact participants’ micronutrient levels. For example, studies conducted in warm, sunny countries may report higher vitamin D levels that don’t necessarily apply to people in other climates.

While there are many conclusions that can be drawn from this data, it’s essential to bear the context of these studies in mind. What works for one patient or hair loss condition may not be appropriate for another.

You’ve been diagnosed with a vitamin deficiency. Will taking supplements help?

Unfortunately, it’s not that simple. There are clear links between hair loss and low levels of some micronutrients — particularly vitamin D and iron. So it’s easy to conclude that taking vitamin supplements could be a cheap, fast way to reduce hair loss, or even promote regrowth.

But it doesn’t work like this in reality.

Most cases of hair loss have more than one cause. Vitamin deficiency may be a contributing factor, but it’s unlikely to be the only or even main cause of hair loss. So compensating for low vitamin levels with a supplement probably won’t reduce hair loss altogether.

If vitamin deficiency is the sole cause of hair loss, supplementation may help with regrowth. But it’s not guaranteed, as people with vitamin deficiencies may have irreversible hair loss.

Hair loss is also a delayed reaction to a trigger. So even if increasing vitamin intake can prevent or slow hair loss, it may be too late to treat the condition with supplements by the time you notice or decide to act on your hair loss.

But there may be real-world circumstances in which vitamin supplements can improve hair loss. We’ve analysed the results of 9 further studies to see if and how vitamin supplements might actually promote hair growth.

It’s also important to note that the results below are independent of the research into vitamin deficiencies and hair loss above. Participants in the studies below may not have a vitamin deficiency or even inadequacy, so there’s not necessarily a link between vitamin supplementation and vitamin deficiency. These studies also don’t account for the hair loss type, so what works for one hair loss patient may not work for another.

Top Ranking Vitamins For Hair Count Change

Here are how 10 of the most popular vitamin supplements rank for hair count changes, according to scientific research studies.

1. Vitamin E

Vitamin E has been associated with successful hair regrowth in alopecia areata patients [36]. This vitamin is an antioxidant that can prevent oxidative stress, which has been linked with alopecia areata [37].

However, excessive vitamin E intake can have serious side effects, including blood thinning, blood clots, and even stroke [45-46]. So it’s best to consult your doctor before taking additional doses of vitamin E — particularly if you have underlying health conditions.

Vitamin E supplement research details

A study into the efficacy of vitamin E for patients with miscellaneous hair loss found a hair count change of +15.2% after 4 months and +34.5% after 8 months of taking the supplement [36].

2. Zinc

Low zinc levels have been linked with development of alopecia areata, male pattern baldness, and female pattern hair loss.
Some hair loss patients taking zinc supplements saw a significant improvement in hair thickness, though the hair count change was low. So while zinc supplements probably can’t treat hair loss, it may make hair appear thicker.

Zinc supplement research details

  • A study of 73 women aged 15-45 with miscellaneous hair loss found that hair thickness improved by 5% over 4 months of zinc supplementation [38].
  • A study of 38 alopecia areata patients taking zinc supplements found no difference in hair count or thickness over 3 months [39].
  • 67% of 15 alopecia areata patients reported positive results after taking a zinc supplement, but these results weren’t statistically significant [40].

3. Niacin

There’s no evidence to suggest that oral vitamin B supplements can improve hair loss. However, topical niacin (vitamin B3) solutions may help.

Niacin supplement research details

  • One study found statistically significant improvements in 69% of 44 female pattern hair loss patients following use of topical niacin, although these weren’t assessed quantitatively [41].

4. Iron

Iron is one of the more widely studied supplements, but it’s generally accepted that iron supplements on their own have limited benefits for hair regrowth. Supplements like L-lysine may improve the absorption of iron, increasing the benefits you can get from it. Supplements combining iron and L-lysine in a single pill are now available.

Iron supplement research details

  • One study found that iron supplements didn’t stop or reverse hair loss in any of the 5 patients experiencing chronic telogen effluvium it studied. These patients all had low iron stores [42].
  • Another study examined iron and L-lysine supplementation in 22 women with chronic telogen effluvium. Researchers found that taking iron and L-lysine supplements daily for 6 months reduced hair shedding by 39%. However, iron supplements alone didn’t have the same effect. Lysine improves iron’s intestinal absorption [42-43].

5. Biotin

Biotin has never been assessed independently for its effectiveness as a hair loss supplement. But research suggests supplements may be useful if a patient has a) a biotin deficiency and b) an underlying health condition [44].

Biotin supplements are unlikely to promote hair growth if you don’t have a biotin deficiency or an underlying condition.

Biotin supplement research details

  • A systematic review of published cases found that biotin supplements only caused clinical improvements in patients with underlying health conditions and an established biotin deficiency [44].

6. Vitamin C

There’s currently no evidence to suggest that vitamin C supplements can reduce hair loss or improve regrowth [45-46]. But it’s still important to get enough vitamin C in your diet to stimulate collagen production and increase iron absorption.

7. Vitamin D

Vitamin D plays a bigger role in hair loss than perhaps any other micronutrient. But despite this, there have been no major published studies into the effect of vitamin D supplements on hair regrowth.

Many people in the UK have inadequate levels of vitamin D, thanks to the lack of year-round sunlight. So regardless of the impact on hair loss, the NHS recommends most people in the UK take a daily vitamin D supplement in autumn and winter [47].

8. Folate

There’s a tentative link between lack of folate and alopecia areata [22]. However, two other studies also found no link between the two, so it remains unclear if folic acid plays a part in this type of hair loss [20-21].

9. Selenium

No links have been established between hair loss and selenium shortage.

10. Vitamin A

Taking too many vitamin A supplements can actually make hair loss worse [48]. In fact, hair loss is a known side effect for some patients who take vitamin A derivatives like retinoids to treat acne and other skin conditions [49].

You shouldn’t take vitamin A supplements to treat hair loss. If you see hair loss as a result of vitamin A or retinoid tablets, speak to your doctor or a trichologist about how to manage this.

Vitamin A supplement research details

  • In a study examining 30 patients with acne (15 women and 15 men aged 18 to 27), vitamin A supplements were linked with a hair count change of -5.5% and a hair thickness change of -3% [48].

Should you take vitamin supplements for hair loss?

Vitamin and mineral supplements aren’t the best way for most healthy people to get their recommended vitamin intake [50-51]. Eating a balanced diet is a far better way to ensure you’re getting the hair nutrients you need.

If you have a known micronutrient deficiency, supplementing your diet with vitamin tablets can help you reach a healthy level. However, be mindful that certain vitamins (like vitamin A) can make hair loss worse if taken in excess.

There’s very little evidence to suggest that vitamin supplements work for hair growth or to reduce hair loss. Vitamin E is the only supplement that shows significant promise for treating hair loss.

That said, vitamin supplements may be helpful in combination with other hair restoration methods, such as medication, topical solutions, low-laser light therapy, and hair transplants. These methods are far more established and effective at tackling all types of hair loss.

Do Vitamins Really Promote Hair Growth? A Systematic Review Of The Science, Wimpole Clinic

Sources:

  1. Public Health Reports | The National Nutrition Conference
  2. Why Vitamins and Other ‘Dietary Supplements’ Can Contain Anything
  3. How the dietary supplement industry keeps regulation at bay
  4. Telogen effluvium: a comprehensive review
  5. Vitamin D Deficiency
  6. The Experimental Induction of Vitamin A Deficiency in Humans
  7. What the Science Says About the Health Benefits of Vitamins and Supplements
  8. Emergency Department Visits for Adverse Events Related to Dietary Supplements
  9. Micronutrient Inadequacies in the US Population: an Overview
  10. What causes alopecia areata?
  11. Vitamin D and the Immune System
  12. Antioxidants and lipid peroxidation status in the blood of patients with alopecia
  13. Vitamin D deficiency in alopecia areata
  14. An investigation of vitamin D status in alopecia areata
  15. Correlation of vitamin D and vitamin D receptor expression in patients with alopecia areata: a clinical paradigm
  16. Analysis of Serum Zinc and Copper Concentrations in Hair Loss
  17. Evaluation of serum zinc level in patients with newly diagnosed and resistant alopecia areata
  18. Comparison of zn, cu, and fe content in hair and serum in alopecia areata patients with normal group 
  19. Decreased serum ferritin is associated with alopecia in women
  20. Serum vitamin B12, folate, ferritin, and iron levels in Turkish patients with alopecia areata
  21. Serum holotranscobalamine, vitamin B12, folic acid and homocysteine levels in alopecia areata patients
  22. Evaluation of serum homocysteine, high-sensitivity CRP, and RBC folate in patients with alopecia areata
  23. The antioxidant role of paraoxonase 1 and vitamin E in three autoimmune diseases
  24. Serum biotin and zinc in male androgenetic alopecia
  25. Understanding Pattern Hair Loss—Hair Biology Impacted by Genes, Androgens, Prostaglandins and Epigenetic Factors
  26. Does tissue iron status have a role in female alopecia?
  27. Serum ferritin and vitamin d in female hair loss: do they play a role?
  28. Serum Vitamin D3 Level in Patients with Female Pattern Hair Loss
  29. Possible association of female-pattern hair loss with alteration in serum 25-hydroxyvitamin D levels
  30. The role of anemia and vitamin D levels in acute and chronic telogen effluvium
  31. Biotin Deficiency in Telogen Effluvium: Fact or Fiction?
  32. Assessment of heavy metal and trace element levels in patients with telogen effluvium
  33. Iron Status in Diffuse Telogen Hair Loss among Women
  34. Prevalence of Iron Deficiency with and without Anemia in Recreationally Active Men and Women
  35. Androgenetic alopecia in women and men: Italian guidelines adapted from European Dermatology Forum/European Academy of Dermatology and Venereology guidelines
  36. Effects of Tocotrienol Supplementation on Hair Growth in Human Volunteers
  37. Oxidative stress in alopecia areata: a systematic review and meta-analysis
  38. Comparing the effects of zinc sulfate, calcium pantothenate, their combination and minoxidil solution regimens on controlling hair loss in women: A randomized controlled trial
  39. Oral zinc sulphate in alopacia areata–a double blind trial 
  40. The therapeutic effect and the changed serum zinc level after zinc supplementation in alopecia areata patients who had a low serum zinc level
  41. A pilot study evaluating the efficacy of topically applied niacin derivatives for treatment of female pattern alopecia
  42. There is no clear association between low serum ferritin and chronic diffuse telogen hair loss
  43. Nutritional factors and hair loss
  44. A Review of the Use of Biotin for Hair Loss
  45. Clinical efficacy of popular oral hair growth supplement ingredients
  46. The Role of Vitamins and Minerals in Hair Loss: A Review
  47. Vitamin D | NHS
  48. Evaluation of biophysical skin parameters and assessment of hair growth in patients with acne treated with isotretinoin
  49. Comparing the frequency of isotretinoin-induced hair loss at <0.5-mg/kg/d versus ≥0.5-mg/kg/d dosing in acne patients: A systematic review
  50. Stop Wasting Money on Vitamin and Mineral Supplements
  51. The balance between food and dietary supplements in the general population
Dr. Michael May (FRCS)
Medically reviewed by Dr. Michael May (FRCS)Updated on January 27, 2023
The Wimpole Clinic offers FUE Hair, Beard & Eyebrow Transplants & Trichology.
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Dr. Michael May (FRCS)
Medically reviewed by
Dr. Michael May (FRCS)
Updated on January 27, 2023

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