Which Vitamin Deficiency Causes Hair Loss

Hair loss is widespread and may have a detrimental psychological and emotional impact. Micronutrients influence hair follicle growth as well as follicle immune activity. Hair loss from insufficiency and deficiency of vitamins are common problems in developed and underdeveloped countries.

A study on the prevalence of vitamin deficiencies in a healthy urban adult population showed a high prevalence of vitamin deficiency among healthy adults. This is a possible risk factor for vitamin deficiency hair loss among different populations.

In this post, we’ll discuss which vitamin deficiency causes hair loss.

Vitamin Deficiencies That Cause Hair Loss

So which vitamin deficiency causes hair loss? Among the most common vitamin deficiencies and insufficiencies that cause hair loss are:

  • Vitamin D
  • Vitamin B complex
  • Vitamin E
  • Vitamin C
  • Vitamin A

Which Vitamin Deficiency Causes Hair Loss - Graph of Vitamin Deficiencies

Vitamin D

Approximately 1 billion people worldwide suffer from vitamin D deficiency. Around 50% of the global population has vitamin D insufficiency study shows.

Vitamin D also referred to as calciferol, is a fat-soluble vitamin. Its primary source is from the sun. Vitamin D is an important vitamin also found in supplements, fortified foods, and foods such as liver, egg yolk, oily fish, and red meat.

The function of vitamin D in hair growth

The role of vitamin D in hair growth is to;

  1. Regulate the immune system
  2. Maintain skin homeostasis
  3. Control hair cycle

Regulate immune system

Hair growth requires a stable immune system that protects the hair follicles from external and internal attacks. The innate and adaptive immune system keeps infections away from the hair follicles and their environment.

Vitamin D promotes the production of microbe-fighting proteins to boost hair follicle immune cells.

It also modulates inflammatory responses on the scalp keeping the environment around the hair follicles conducive enough for hair to grow.

Maintain skin homeostasis

Skin homeostasis is the skin’s state of stability that enables it to function at its optimum. Vitamin D ;

  • regulates the process of apoptosis which is the cell death and replacement on the skin.
  • It also regulates the formation of epithelial cells, which form the skin tissue.

Hair follicles, part of the skin appendages, require optimal skin homeostasis to grow and develop.

Control hair cycle

The hair growth cycle contains three main stages.

  • Growth phase – anagen

In anagen, hair follicle cells go through mitosis, differentiate to form the hair strand and elongate towards the scalp. The anagen phase lasts between 2-6 years.

  • A transition phase – catagen

In the catagen phase, the active growth ceases, and hair follicles get into an inactive phase. This period lasts 2-3 weeks.

  • Resting phase – telogen.

During the anagen phase, the hair shaft detaches from the hair follicle and is kicked out of the scalp to give room for a new hair strand formation.

New hair forms during the growth phase, where a hair-forming protein known as keratin is produced by keratinocyte cells. Vitamin D enables the keratinocytes to regulate the growth and shedding phases of the hair cycle.

Hair loss in vitamin D deficiency

Which Vitamin Deficiency Causes Hair Loss - Vitamin D Deficiency

The deficiency of vitamin D causes different types of hair loss.

  • Telogen effluvium
  • Androgenetic alopecia
  • Alopecia areata
  • Scarring alopecia
  • Psoriasis

1. Telogen effluvium

Telogen effluvium refers to the excessive shedding of hair that happens at least three months from the onset of a trigger. Lower levels of vitamin D could trigger an episode of telogen effluvium. Vitamin D promotes hair cycling. Deficiency or insufficiency hinders the keratinocytes from effectively controlling the hair cycle and stem cell renewal. It causes the hair to move prematurely from the growing phase and enter the shedding phase. Deficiency also shortens the growth phase significantly.

2. Androgenetic alopecia

Androgenetic alopecia is one of the most common types of hair loss among men and women. About 50% of men experience androgenetic alopecia by the time they are 50 years.

A deficiency in vitamin D causes:

  • premature onset of androgenetic alopecia,
  • It also increases the likelihood of developing androgenetic alopecia in genetically predisposed people,
  • Studies show that most people with androgenetic alopecia also have low serum levels of vitamin D.

3. Alopecia areata

Alopecia areata is a non-scarring hair loss. This type of hair loss presents as patches on the scalp, eyebrows, and beard. Alopecia areata is an autoimmune-mediated hair loss associated with decreased systemic immunity and a decline in hair follicle immune privilege. Immune privilege is the ability of the hair follicles to tolerate high amounts of stress from illness or inflammation without succumbing to it.

A deficiency in vitamin D leads to lowered immunity and may cause the emergence of autoimmune hair loss.

4. Scarring alopecia

Scarring alopecia refers to a group of hair loss conditions that cause permanent destruction of hair follicles. These conditions are

  • Lichen planopilaris
  • Frontal fibrosing
  • Folliculitis decalvans
  • Central centrifugal cicatricial alopecia
  • Pseodepelade

The primary cause of permanent loss of hair follicles is an immune attack on the hair follicle stem cells. Insufficient or deficient vitamin D levels predispose one to scarring alopecia which also causes a decline in systemic immunity and hair follicle immune privilege.

5. Psoriasis

Psoriasis is an autoimmune-mediated hair loss that causes flaky patches on the scalp. The immune system mistakenly attacks healthy cells on the scalp and causes inflammation. The skin sheds in 14 -21 days instead of 30 days.

Low vitamin D levels leading to lowered immunity are associated with frequent psoriatic flares among psoriatic patients.

What causes vitamin D deficiency

  • Gut diseases; Crohn’s disease, celiac disease, cystic fibrosis, and pancreatitis hinder adequate nutritional absorption.
  • People living in cold areas with less sunshine are at a high risk of vitamin D deficiency.
  • Skin color. Dark-skinned people have more melanin than light-skinned people and absorb less vitamin D.
  • The use of sunscreen may hinder adequate UV rays penetration.

Classification of vitamin D status

Concentration  Classification
<10ng/mL Deficient
11-20ng/mL Insufficient
>20ng/mL Optimal

Vitamin B complex

Vitamin B complex is composed of 8 water-soluble B vitamins.

  • B1-thiamin
  • B2-riboflavin
  • B3-niacin
  • B5-pantothenic acid
  • B6-pyridoxine
  • B7 biotin
  • B9 folate
  • B12 – cobalamin

Riboflavin, biotin, folate, and vitamin B12 deficiency cause hair loss. About 1.5 to 15% of people are deficient in vitamin B12 alone.

Liver, chicken, seafood, eggs, leafy greens, dairy products, legumes, seeds, and fortified foods are some of the best sources of B vitamins.

Which Vitamin Deficiency Causes Hair Loss - Vitamin B12 Deficiency

The function of vitamin B complex in hair growth

Generally, B vitamins enhance metabolic activities within the hair follicle enabling the cells to utilize nutrients to their optimum and promote cell turnover.

Vitamin B2 Hair follicle cells are the second fastest multiplying cells in the body after bone marrow. They require large amounts of energy to function normally. Riboflavin plays a part in hair follicle cellular development and energy production.
Vitamin B7 Known as vitamin H or biotin. Biotin synthesizes proteins and promotes keratin formation for healthy hair growth.
Vitamin B9 Folate helps in keratinization and cell formation during the active phase of hair growth.
Vitamin B12 Vitamin B12 promotes nucleic acid production, which is key to hair follicle genetic programming.

Hair loss in vitamin B deficiency

Which Vitamin Deficiency Causes Hair Loss - Vitamin B Deficiency

Vitamin B deficiency causes

  • Telogen effluvium
  • Hair thinning
  • Congenital hair loss

1. Telogen effluvium

Excessive hair shedding can be associated with low levels of Riboflavin, biotin, folate, and vitamin B12. The hair shedding may persist until the deficiency resolves.

2. Hair thinning

Hair thinning may be a result of vitamin B12 deficiency. Biotin deficiency which may be congenital or acquired ,leads to biotinidase deficiency hair loss.

3. Congenital hair loss

Congenital hair loss is hair that is present at birth, seen in infants born with a biotin deficiency from a defect in biotinidase enzyme synthesis.

What causes vitamin B deficiency

  • Inadequate absorption of vitamin B12 from lack of intrinsic factors. Intrinsic factor is a protein found in the intestines that help with the absorption of vitamin B 12.
  • Prolonged use of medication that affects the gut
  • Dietary deficiencies – Vegans and vegetarians are at a high risk of vitamin B deficiencies as they do not consume animal products that are rich sources of B vitamins.
  • Congenital defects include biotinidase deficiency. The body cannot synthesize biotin.

Classification of vitamin B status

Vitamin Concentration Classification
B12 >200pg/mL deficient
>200pg/mL Optimal
Biotin 133-329pmol/L Optimal
18-127nmol/24hrs Deficient
Folate 2ng/mL Deficient
>4ng/mL Normal
2-4ng/mL Borderline

Vitamin A

Vitamin A, known as retinol, is a fat-soluble vitamin found in plants, animal sources, fortified foods, and supplements. According to the World Health Organization, vitamin A deficiency is a public health problem affecting more than half of all countries. Studies show that an estimated 140 million children and over 7 million pregnant women suffer from vitamin A deficiency worldwide.

Functions of vitamin A on hair growth

  • Vitamin A acts as an antioxidant and promotes the formation of melanin, the pigment that gives the skin and hair the natural color.
  • Vitamin A regulates hair follicle stem cells and influences the hair follicle cycle.
  • Regulation of certain elements such as zinc and hormones such as the thyroid hormone play significant roles in hair follicle growth and development.
  • Supports the production and regulation of sebum on the scalp. Sebum provides lubrication of the hair and scalp, preventing dryness.

Hair loss in vitamin A

Which Vitamin Deficiency Causes Hair Loss - Hair Thinning in Vitamin A Deficiency

Vitamin A deficiency causes:

  • Follicular hyperkeratosis
  • Hair breakage
  • Hair thinning

Follicular hyperkeratosis

Follicular hyperkeratosis is a build-up of keratin around the hair follicles. It may be a result of vitamin A deficiency. This condition causes the formation of bumps on the skin around areas with hair follicles and may cause hair loss.

Hair breakage

Lack of sufficient levels of vitamins causes dry hair. Dry hair is brittle and prone to breakage and could lead to hair loss from breakage.

Hair thinning

Insufficient levels of vitamins affect zinc and thyroid levels in the body. Zinc deficiency and low thyroid levels could lead to hair thinning and sometimes worsen existing hair loss conditions such as androgenetic alopecia.

What causes vitamin A deficiency

  • Inadequate dietary intake
  • Fat malabsorption
  • Liver disorders

Classification of vitamin A status

Concentration Classification
20-60mcg/dL Optimal

Vitamin  E

Vitamin E is a fat-soluble vitamin found in grains, vegetable oils, meat, poultry, eggs, and fruits. Studies show that only one-fifth of the global population has ideal levels of vitamin E, while the rest four-fifths are either deficient or have inadequate levels.

Functions of vitamin E on hair growth

  • Vitamin E acts as an antioxidant and reduces oxidative stress on the scalp and around the hair follicles. Oxidative stress is the cell imbalance that may lead to inflammation and diseases from damage by free radicals and could cause hair loss.
  • Vitamin E is the most prevalent fat soluble on the skin regulating cell activities such as metabolism, cell signaling, and hormone balance, all of which are essential for new hair growth and development.
  • It supports the production of collagen, an essential component in hair formation. Vitamin E protects against collagen cross-linking, which induces skin aging and hair thinning.

Hair loss in vitamin E

Autoimmune-mediated hair loss

Vitamin E deficiency exacerbates oxidative stress that leads to inflammation and the emergence of autoimmune hair loss like alopecia areata and other scarring types of hair loss.

What causes vitamin E deficiency

Hereditary illnesses like abetalipoproteinemia and ataxia, as well as Crohn’s disease AND cystic fibrosis, could lead to vitamin E deficiency.

Classification of vitamin E status

Concentration Classification
5.5-17ug/mL Optimal(adults)
3-18.4ug/mL Optimal(children)

Vitamin C

Vitamin C, known as ascorbic acid, is a water-soluble vitamin found mostly in fruits.

Vitamin C deficiency is prevalent worldwide but is predominantly in low and middle-income regions while affecting 1 in 20 people in developed countries.

Functions of vitamin C on hair growth

  • Vitamin C plays an essential role in the absorption and assimilation of iron in the body. Iron is a significant component in forming hemoglobin, a protein that forms the blood and nourishes hair follicles for optimum growth and development.
  • Ascorbic acid is also associated with promoting the elongation of hair shafts via the insulin growth factor.
  • Vitamin C helps produce collagen, a major component in skin and hair follicle formation.
  • Improved copper synthesis helps with melanin formation during hair formation.
  • Normal formation of hair follicles connective tissues that help anchor the hair follicles in place.

Hair loss in vitamin C

Which Vitamin Deficiency Causes Hair Loss - Hair loss in lack of vitamin C

  • Vitamin C deficiency may lead to dry, brittle hair and cause hair loss from hair breakage
  • Lack of vitamin C results in corkscrew hairs. These are coily hairs resembling corkscrews that are a symptom of vitamin C deficiency.
  • Loose anagen syndrome hair loss occurs when there is a defect in the normal formation of connective tissues in the hair follicles. The hair comes off easily on slight pulling.

What causes vitamin C deficiency

  • People with iron excess, which causes the kidneys to waste vitamin C
  • Alcoholism
  • Dietary insufficiency
  • Gastrointestinal disorders leading to malabsorption

Classification of vitamin C status

Concentration Classification
<0.2mg/dl Deficient
<0.6mg/dl Marginal
>0.6 – 2mg/dl Optimal


Vitamin deficiency is one of the leading causes of hair loss. The lack of specific vitamins from dietary insufficiency or underlying conditions contributes to a significant percentage of people suffering from hair loss.

Vitamins play an important role in overall health. Figuring out which vitamins you’re lacking could be one of the best treatments for balding in men and help treat male-pattern hair loss. In fact, a lot of female celebrities suffer from hair loss due to stress and vitamin deficiencies. Now that you know which vitamin deficiency causes hair loss, it’s time to start a balanced diet to prevent nutritional deficiencies. A healthy diet that includes essential nutrients could help combat the common causes of hair loss.

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