7 Nutritional Deficiencies That Can Cause Hair Loss: Signs, Tests and Treatment

Nutritional deficiencies can contribute to hair loss when the body does not receive or absorb enough of the nutrients needed for normal follicle function.

Hair follicles need protein, energy, vitamins, minerals, oxygen and normal cellular activity to maintain the hair-growth cycle. When an important nutrient becomes deficient, more hairs may enter the resting or shedding phase. As a result, you may notice diffuse shedding, reduced density, weaker strands or slower recovery.

However, hair loss does not automatically mean that you have a vitamin or mineral deficiency.

Genetics, androgenetic alopecia, thyroid disease, hormonal changes, illness, medication, stress, rapid weight loss, autoimmune disease, inflammation and scalp conditions can produce similar symptoms.

Therefore, the safest approach is to identify the pattern of hair loss first and then use targeted testing when a nutritional problem is reasonably suspected.

This guide explains seven nutritional deficiencies that may contribute to hair loss, how each nutrient affects the body, which symptoms may appear, which tests may be useful and why taking high-dose supplements without evidence of deficiency can sometimes make matters worse.

Medical note: This article provides general educational information only. It does not diagnose a nutritional deficiency or hair-loss condition and does not replace advice from a doctor, dermatologist, registered dietitian, pharmacist or another appropriately qualified healthcare professional.

7 Nutritional Deficiencies Linked With Hair Loss: Quick Comparison

How Nutritional Deficiencies Can Affect Hair Growth

Hair follicles contain rapidly dividing cells. Therefore, they need adequate calories, protein, amino acids, vitamins, minerals and oxygen.

A significant deficiency, restrictive diet, illness or rapid weight loss can disrupt the normal hair-growth cycle.

As a result, more follicles may move from the active growth phase into the resting phase. Increased shedding may then appear several weeks or months after the original trigger.

This pattern is often called telogen effluvium. It usually causes diffuse shedding across the scalp rather than one isolated bald area.

Hair Loss May Have More Than One Cause

A nutritional deficiency may occur alongside another hair-loss condition.

For example, someone may have depleted iron stores and androgenetic alopecia at the same time. Correcting the iron deficiency may improve an overlapping shedding problem, but it will not directly reverse genetic follicular miniaturisation.

Likewise, nutritional treatment alone cannot stop active scarring alopecia, autoimmune hair loss or another inflammatory disease.

Symptoms Cannot Confirm a Deficiency

Fatigue, brittle nails, dry skin, poor concentration, shedding and weak hair may occur with several nutritional deficiencies.

However, these symptoms can also occur with thyroid disease, illness, medication, sleep problems, stress and other conditions.

Therefore, targeted laboratory testing and clinical assessment are more useful than choosing supplements from a symptom list.

1. Vitamin D Deficiency and Hair Loss

The body uses vitamin D for bone health, immune regulation and normal cellular activity.

Vitamin D receptors are also present in hair follicles. Consequently, researchers have studied possible relationships between vitamin D status and several hair-loss conditions.

Some studies have reported lower vitamin D levels in people with alopecia areata, telogen effluvium, androgenetic alopecia and other forms of hair loss.

However, an association does not prove that low vitamin D caused every case.

When testing confirms deficiency, correcting it may support general health and normal follicle biology. Even so, vitamin D should not replace diagnosis-specific treatment for another condition.

Possible Signs of Vitamin D Deficiency

A person with low vitamin D may have no obvious symptoms.

When symptoms occur, they may include:

• Fatigue or low energy.
• Muscle weakness or aches.
• Bone discomfort.
• Low mood.
• Increased shedding occurring alongside other deficiency symptoms.

These symptoms are not specific to vitamin D deficiency. A 25-hydroxyvitamin D blood test is commonly used to assess vitamin D status.

Hair-loss supplements work best when they address a real nutritional need rather than an assumed deficiency.

How to Address Low Vitamin D

1. Ask whether testing is appropriate. A healthcare professional may use a 25-hydroxyvitamin D blood test.
2. Include vitamin D-containing foods. Fatty fish, egg yolks, fortified milk, fortified plant-based drinks and selected cereals can contribute to intake.
3. Use sunlight safely. Vitamin D production varies with skin pigmentation, season, location, age, clothing and other factors.
4. Match supplementation to the result. The appropriate dose depends on the blood level and individual medical situation.
5. Avoid unnecessary high doses. Excess vitamin D can cause toxicity and high blood calcium.

For a detailed discussion of testing, treatment and recovery, read Vitamin D3 Deficiency and Hair Loss.

2. Iron Deficiency and Hair Shedding

Iron helps the body produce haemoglobin, which transports oxygen through the bloodstream. It also supports cellular metabolism and many enzyme systems.

Iron stores may become depleted because of heavy menstrual bleeding, pregnancy, gastrointestinal blood loss, restricted diets, repeated blood donation or poor absorption.

When iron deficiency becomes clinically significant, it may contribute to diffuse shedding.

However, hair loss has many possible causes. Therefore, iron results should form part of a broader assessment.

How Iron and Ferritin Relate to Hair Health

Ferritin is a protein that stores iron. Clinicians often measure serum ferritin when evaluating possible iron deficiency.

A low ferritin result can indicate depleted reserves. However, inflammation, infection, liver disease and other conditions may raise ferritin.

Therefore, ferritin should not always be interpreted alone.

A clinician may also review:

• Complete blood count.
• Serum iron.
• Transferrin or total iron-binding capacity.
• Transferrin saturation.
• Inflammatory markers when appropriate.
• Symptoms, diet and blood-loss history.

There is no single ferritin level that guarantees hair growth for every person.

For more detail, read Ferritin Deficiency and Hair Loss.

Possible Signs of Iron Deficiency

• Fatigue or weakness.
• Shortness of breath.
• Pale skin.
• Dizziness or headaches.
• Cold hands or feet.
• Brittle nails.
• Restless legs.
• Diffuse hair shedding.

Seek medical evaluation when iron deficiency is suspected. The cause of the deficiency may require treatment as well as iron replacement.

How to Address Iron Deficiency

1. Request appropriate testing. Ferritin, CBC and iron studies may help establish whether deficiency is present.
2. Identify the cause. Heavy periods, gastrointestinal blood loss, pregnancy, restricted intake and malabsorption require different solutions.
3. Eat iron-rich foods. Red meat, poultry, seafood, lentils, beans, tofu, leafy vegetables and fortified cereals provide iron.
4. Combine plant iron with vitamin C. Citrus fruits, berries, peppers and tomatoes can improve non-haem iron absorption.
5. Review absorption blockers. Tea, coffee, calcium and some medicines may interfere when taken close to iron.
6. Use supplements only when indicated. Excessive iron can cause serious harm.

For product and formulation differences, see the iron supplement comparison for hair loss.

3. Zinc Deficiency and Hair Loss

Zinc supports immune function, wound healing, DNA synthesis, protein production and normal cell division.

These processes matter to rapidly growing tissues, including hair follicles.

A genuine zinc deficiency can contribute to hair loss, skin changes, impaired wound healing, changes in taste or smell and reduced immune function.

However, extra zinc does not reliably improve hair growth when zinc status is already adequate.

How Zinc Supports Hair Follicles

The body needs zinc to produce proteins and DNA. Zinc also supports enzymes involved in cellular repair and growth.

Low zinc levels have been reported in some people with alopecia areata, telogen effluvium and other hair-loss conditions.

Nevertheless, supplementation should address a genuine deficiency or clearly identified need.

Long-term high-dose zinc can reduce copper absorption. In turn, copper deficiency may cause anaemia, neurological problems and other health effects.

Who May Be at Greater Risk?

Risk factors may include:

• Severely restrictive diets.
• Digestive disease or malabsorption.
• Long-term diarrhoea.
• Alcohol-use disorder.
• Pregnancy or breastfeeding with inadequate intake.
• Other medical conditions affecting nutrient absorption or requirements.

How to Improve Zinc Intake

1. Choose zinc-rich foods. Oysters, beef, poultry, crab, dairy products, beans, nuts, seeds and whole grains provide zinc.
2. Use varied food sources. Plant sources contain zinc, although phytates can reduce absorption.
3. Include dairy when appropriate. Yogurt and cheese provide both zinc and protein.
4. Avoid high-dose self-treatment. More zinc is not necessarily better.
5. Consider copper balance. Long-term high-dose zinc may require professional review.

4. Biotin Deficiency and Hair Changes

Biotin, also called vitamin B7, helps enzymes process fats, carbohydrates and amino acids.

Because biotin is involved in normal metabolism, it is frequently added to supplements marketed for hair, skin and nails.

A genuine biotin deficiency can cause thinning hair, skin rash, brittle nails and neurological symptoms.

However, true deficiency is uncommon in people eating a varied diet.

Most people with hair loss do not have isolated biotin deficiency. Therefore, high-dose biotin is unlikely to solve hair loss caused by androgenetic alopecia, thyroid disease, low iron, stress or inflammatory disease.

Who May Develop Biotin Deficiency?

Possible risk situations include:

• Rare inherited disorders such as biotinidase deficiency.
• Long-term consumption of large quantities of raw egg white.
• Severe malnutrition.
• Long-term intravenous nutrition without adequate biotin.
• Selected medication or absorption problems.

Biotin and Hair Strength

Biotin supports normal metabolic processes used by keratin-producing tissues.

However, taking more biotin does not automatically produce faster or denser hair growth when nutritional status is already adequate.

When a genuine deficiency exists, correction may improve deficiency-related symptoms.

Food Sources of Biotin

• Cooked eggs.
• Liver and other organ meats.
• Salmon.
• Almonds and walnuts.
• Sunflower seeds.
• Milk and selected dairy products.
• Sweet potatoes.
• Whole grains.

Important Biotin Blood-Test Warning

High-dose biotin can interfere with certain laboratory tests.

Depending on the laboratory method, this may affect thyroid tests, hormone measurements, vitamin D testing and cardiac markers such as troponin.

Therefore, tell your doctor and laboratory staff about every biotin-containing product you use.

Follow their instructions about whether supplementation should be stopped before blood testing.

5. Vitamin C Deficiency and Hair Health

Vitamin C supports collagen production, antioxidant defence, wound healing and absorption of non-haem iron.

Severe deficiency can cause scurvy.

Possible symptoms include fatigue, gum problems, easy bruising, poor wound healing and characteristic changes around hair follicles.

Low vitamin C may also worsen iron deficiency by reducing absorption of plant-based iron.

However, isolated vitamin C deficiency is not a common explanation for hair loss in people eating a varied diet.

How Vitamin C May Affect Hair

Vitamin C contributes to collagen formation and antioxidant protection.

Its effect on iron absorption may be especially relevant for people who obtain much of their iron from plant foods.

Nevertheless, taking large amounts of vitamin C will not treat androgenetic alopecia or another unrelated hair-loss condition.

Possible Signs of Severe Vitamin C Deficiency

• Fatigue or weakness.
• Easy bruising.
• Bleeding or swollen gums.
• Poor wound healing.
• Dry or rough skin.
• Corkscrew-shaped body hairs in severe deficiency.
• Iron deficiency that may be worsened by poor absorption.

Food Sources of Vitamin C

• Citrus fruits: Oranges, grapefruit, lemons and limes.
• Berries: Strawberries, blackcurrants and raspberries.
• Bell peppers: Red and yellow peppers are particularly rich sources.
• Kiwi and guava: Both provide substantial vitamin C.
• Broccoli and Brussels sprouts: These vegetables also provide fibre and other nutrients.
• Leafy vegetables: Spinach and kale provide vitamin C and folate.

For most people, a varied diet can provide adequate vitamin C.

6. Vitamin E Deficiency and Scalp Health

Vitamin E is a fat-soluble antioxidant that helps protect cell membranes from oxidative damage. It also contributes to immune and skin function.

A genuine deficiency is uncommon.

When vitamin E deficiency occurs, an underlying disorder affecting fat absorption is often involved.

Evidence does not show that routine high-dose vitamin E supplementation reliably treats hair loss in people with adequate nutritional status.

In addition, excessive supplementation may increase bleeding risk or interact with medicines.

How Vitamin E Supports the Skin and Scalp

Vitamin E contributes to antioxidant protection and normal skin-barrier function.

These roles support general scalp health.

However, improved scalp nutrition does not automatically reverse genetic follicular miniaturisation, scarring alopecia or autoimmune hair loss.

Who May Be at Risk of Vitamin E Deficiency?

Risk may be higher with:

• Severe fat-malabsorption disorders.
• Certain inherited conditions.
• Selected liver, pancreatic, intestinal or biliary diseases.
• Severe dietary restriction combined with another medical problem.

Food Sources of Vitamin E

1. Almonds and hazelnuts: These provide vitamin E, healthy fats and protein.
2. Sunflower seeds: These can be added to salads, yoghurt or oatmeal.
3. Plant oils: Sunflower, safflower and wheat-germ oils contain vitamin E.
4. Leafy vegetables: Spinach and Swiss chard provide smaller amounts.
5. Avocado: Avocado contributes vitamin E and monounsaturated fat.

Avoid using high-dose vitamin E as a trial-and-error hair treatment.

7. Selenium Deficiency and Hair Loss

Selenium is a trace mineral involved in antioxidant defence, DNA production, reproduction and thyroid hormone metabolism.

Both inadequate and excessive selenium can cause health problems.

Importantly, excessive selenium intake can itself cause hair loss and brittle nails.

Because selenium has a relatively narrow range between nutritional need and excessive intake, high-dose supplementation should not be started simply because hair is shedding.

Why Selenium Balance Matters

Selenium forms part of antioxidant enzymes. It is also involved in thyroid hormone metabolism.

Thyroid disorders can affect hair growth. However, selenium supplementation is not a general treatment for thyroid-related hair loss.

When selenium intake is already adequate, taking more may provide no benefit and can become harmful.

Possible Signs of Selenium Excess

Excessive selenium intake, sometimes called selenosis, may cause:

• Hair loss.
• Brittle or damaged nails.
• Nausea or diarrhoea.
• A metallic taste.
• A garlic-like odour on the breath.
• Skin rash.
• Neurological symptoms in severe cases.

Safer Selenium Guidance

1. Check your total intake. Include multivitamins, hair supplements, thyroid products and stand-alone selenium.
2. Do not diagnose deficiency from hair loss alone. Many more common causes should also be considered.
3. Use Brazil nuts cautiously. Their selenium content can vary considerably.
4. Avoid excessive supplementation. Too much selenium can directly cause hair loss.
5. Investigate thyroid symptoms properly. Thyroid testing may be more useful than assuming selenium is deficient.
6. Ask a qualified professional before using high-dose selenium.

Other Nutritional Factors That Can Affect Hair

The seven nutrients above are commonly discussed in relation to hair loss. However, they are not the only nutritional factors that can affect shedding and hair quality.

Protein Deficiency

Hair shafts are made primarily from keratin, a protein.

Very low protein intake, severe calorie restriction, malnutrition or poor absorption may therefore disrupt the hair-growth cycle.

People following restrictive diets should ensure they receive adequate protein from appropriate animal or plant sources.

Vitamin B12 and Folate

Vitamin B12 and folate support red blood cell formation and DNA synthesis.

A deficiency may cause anaemia, fatigue, neurological symptoms and other health changes.

Low B12 may contribute to hair shedding in selected people, particularly when deficiency is clinically significant or several nutritional problems overlap.

For more detail, read Vitamin B12 and Hair Loss.

Rapid Weight Loss and Low-Calorie Diets

Rapid weight loss, crash diets, eating disorders, bariatric surgery and very low-calorie diets can trigger telogen effluvium.

The trigger may involve inadequate energy, insufficient protein, iron deficiency, zinc deficiency or the physiological stress caused by rapid weight change.

Vitamin A Excess

Vitamin A is essential for normal health.

However, excessive intake can contribute to hair loss.

This is more likely to occur from high-dose supplements or selected medicines than from ordinary food intake.

Check the combined vitamin A content of multivitamins, beauty supplements and other nutritional products before taking them together.

Blood Tests That May Be Considered for Hair Loss

There is no universal laboratory panel that every person with hair loss requires.

Testing should be guided by the hair-loss pattern, symptoms, diet, medical history, medications, menstrual history and examination.

A healthcare professional may consider:

• Complete blood count: Helps assess anaemia and blood-cell patterns.
• Ferritin and iron studies: Help assess iron stores and iron availability.
• Thyroid-stimulating hormone and related thyroid tests: May be appropriate when thyroid dysfunction is possible.
• Vitamin D: Considered when symptoms or risk factors support testing.
• Vitamin B12 and folate: Particularly relevant with restrictive diets, anaemia, gastrointestinal disease or neurological symptoms.
• Zinc or copper: May be considered with deficiency risk, malabsorption or prolonged high-dose supplementation.
• Other targeted tests: Hormonal, inflammatory or autoimmune testing may be appropriate in selected cases.

A trichologist can help document the visible hair and scalp pattern. However, blood testing, diagnosis and medical treatment should be handled by an appropriately qualified clinician.

How Long Does Hair Take to Recover After Correcting a Deficiency?

Hair recovery is slower than correction of many blood abnormalities.

Even when nutritional treatment is effective, follicles need time to progress through the growth cycle.

Recovery varies according to the deficiency, severity, duration, diagnosis, age, genetics and whether another form of hair loss is present.

How to Use Hair Supplements More Safely

Hair supplements often combine multiple vitamins, minerals and botanical ingredients.

As a result, taking several products together can unintentionally duplicate nutrients.

Check Every Label

Compare vitamin A, vitamin D, vitamin E, iron, zinc, selenium, biotin, vitamin B12, folate and other nutrients across every product you use.

Include multivitamins, hair formulas, fortified powders and individual supplements.

Avoid Treating Test Results Without Context

A laboratory result should be interpreted alongside symptoms, medical history, diet, medication and other test results.

A value near the lower end of a laboratory range does not automatically mean high-dose supplementation is required.

Tell Your Clinician What You Take

Bring a complete list of supplements and doses to appointments.

Some products can interact with medication, duplicate other nutrients or interfere with laboratory testing.

Choose Food First Where Practical

A varied diet provides vitamins and minerals together with protein, fibre, carbohydrates, healthy fats and other nutrients.

Supplements may still be appropriate when testing identifies a deficiency, diet cannot reliably provide enough of a nutrient, or another clinical reason exists.

Advanced Trichology Nutritional Support

When Nutrition Is Not the Complete Answer

Correcting a nutritional deficiency will not directly treat every type of hair loss.

Another or additional approach may be required for:

• Androgenetic alopecia.
• Telogen effluvium caused by illness, stress, surgery or medication.
• Alopecia areata.
• Scarring alopecia.
• Thyroid-related hair loss.
• PCOS or another hormonal disorder.
• Traction alopecia.
• Inflammatory or infectious scalp disease.
• Hair-shaft damage and breakage.

If the visible pattern includes a widening part, crown thinning or a receding hairline, nutrition may overlap with genetically driven pattern loss.

Learn more about DHT and hair loss and androgenetic alopecia.

When to See a Trichologist, Doctor or Dermatologist

When to See a Trichologist

Consider a trichology assessment when:

• Diffuse shedding continues for several months.
• You are unsure whether the problem is shedding, thinning or breakage.
• You suspect nutrition is only one part of the problem.
• Several supplements or products have not helped.
• You need structured photographs and progress monitoring.
• You need supportive scalp and hair-care guidance.

When to See a Doctor or Dermatologist

Seek medical assessment when:

• Hair loss begins suddenly or progresses rapidly.
• You develop smooth or irregular bald patches.
• The scalp becomes painful, inflamed, crusted, infected or draining.
• Smooth, shiny or scar-like areas appear.
• You have severe fatigue, weakness, neurological symptoms or unexplained weight change.
• A nutritional deficiency is severe or persistent.
• You have gastrointestinal disease, suspected malabsorption or unexplained anaemia.
• You require prescription treatment or specialist laboratory interpretation.

Frequently Asked Questions About Nutritional Deficiencies and Hair Loss

Common Deficiencies and Hair Shedding

Which vitamin deficiency causes hair loss?

Several deficiencies may contribute to hair loss. These include deficiencies involving vitamin D, biotin, zinc and, in selected situations, vitamin B12, vitamin C or vitamin E. Iron and protein deficiency can also contribute to diffuse shedding. The likely cause depends on your diet, symptoms, medical history, examination and test results.

What nutritional deficiency is most commonly checked for hair loss?

Iron status is frequently assessed in people with diffuse shedding, especially when blood loss, restrictive eating, pregnancy or other risk factors are present. Vitamin D, B12, folate, zinc and thyroid markers may also be considered depending on the individual case.

Can low vitamin D cause hair loss?

Low vitamin D has been associated with several hair-loss conditions. However, an association does not prove that vitamin D deficiency caused the hair loss. Testing and a broader assessment are therefore important.

Can low iron cause hair loss without anaemia?

Yes. Iron stores can become depleted before haemoglobin falls below the laboratory range. Low ferritin may therefore occur without established anaemia. The result should still be interpreted with other iron markers and the clinical picture.

Can zinc deficiency cause hair loss?

A true zinc deficiency can contribute to hair loss and skin changes. However, taking extra zinc when levels are adequate may not help. Excessive zinc can also lead to copper deficiency.

Can a lack of protein cause hair loss?

Yes. Severe protein deficiency, inadequate calorie intake, rapid weight loss or malnutrition can disrupt the hair-growth cycle and trigger diffuse shedding.

Biotin and Hair Supplements

Does biotin really help hair grow?

Biotin can help correct symptoms caused by a true biotin deficiency. However, deficiency is uncommon, and evidence that high-dose biotin improves hair in otherwise healthy people is limited.

Can hair supplements cause hair loss?

Yes. Excessive intake of selenium, vitamin A and some other nutrients can contribute to hair loss. Combining several products may also cause unintended duplication.

Can too many vitamins cause hair loss?

Yes. Excess vitamin A and selenium are recognised causes of hair loss. Excessive iron, zinc or vitamin E can also cause significant health problems.

Can biotin interfere with blood tests?

Yes. High-dose biotin can interfere with certain laboratory assays, including some thyroid, hormone and cardiac tests. Tell your doctor and laboratory staff about biotin use before testing.

Is FoliGROWTH suitable for nutritional hair loss?

FoliGROWTH is a multi-nutrient hair supplement containing several vitamins and minerals discussed in this article. It may fit a broader nutritional-support plan, but it should not replace testing or medical treatment of a confirmed iron, vitamin D, B12 or other deficiency.

Testing, Treatment and Recovery

Should I get blood tests before taking hair supplements?

Targeted testing is often safer than guessing. Depending on your history, a clinician may consider a CBC, ferritin, iron studies, thyroid markers, vitamin D, vitamin B12, folate, zinc or other tests.

What ferritin level is needed for hair growth?

There is no single ferritin level that guarantees hair growth for every person. Ferritin should be interpreted alongside haemoglobin, transferrin saturation, inflammation, symptoms and other causes of hair loss.

How long does hair take to recover after correcting a deficiency?

Shedding may begin to improve over several months when deficiency was an important contributor. Visible density changes may take six months or longer because hair grows slowly.

What if my blood tests are normal but I am still losing hair?

Normal nutritional results do not rule out androgenetic alopecia, thyroid disease, hormonal changes, medication effects, autoimmune hair loss, scalp inflammation, traction, stress-related shedding or hair breakage.

When should I see a professional?

Seek assessment for sudden or severe shedding, bald patches, scalp pain, redness, scaling, scarring, a widening part, a receding hairline or continued hair loss despite correcting a confirmed deficiency.

Conclusion: Can Nutritional Deficiencies Cause Hair Loss?

Nutritional deficiencies can contribute to hair loss, especially when a deficiency is significant enough to affect normal cellular function, blood formation, thyroid function, protein metabolism or the hair-growth cycle.

However, taking every available hair supplement is not the answer.

Iron, zinc, vitamin D, biotin and protein are commonly considered when nutrition-related hair loss is suspected. Vitamin C, vitamin E, selenium, vitamin B12, folate and other nutrients may also matter in selected circumstances.

The safest approach is to identify what is actually deficient, understand why the deficiency developed and correct it appropriately.

If nutritional results improve but hair loss continues, another cause may still be active. Genetics, DHT sensitivity, thyroid disease, hormonal changes, stress, medication, inflammatory disease, autoimmune hair loss and physical breakage should all remain part of the wider assessment.

Next step: Read about ferritin deficiency and hair loss, review vitamin D3 deficiency and hair loss, learn about vitamin B12 and hair loss, compare iron supplements for hair loss, or find a trichologist near you.

Medical disclaimer: This article is for general informational and educational purposes only. It does not provide medical advice, diagnose a nutritional deficiency, interpret laboratory results or recommend an individual supplement or dose. Do not begin, stop, combine or substantially increase iron, vitamin D, zinc, selenium, biotin or other supplements without appropriate guidance. Seek professional care for sudden, severe, patchy, painful, inflamed, scarring or persistent hair loss.

References and Further Reading

1. Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A. The Role of Vitamins and Minerals in Hair Loss: A Review.
2. NIH Office of Dietary Supplements: Vitamin D Fact Sheet for Health Professionals
3. NIH Office of Dietary Supplements: Iron Fact Sheet for Health Professionals
4. NIH Office of Dietary Supplements: Zinc Fact Sheet for Health Professionals
5. NIH Office of Dietary Supplements: Biotin Fact Sheet for Health Professionals
6. NIH Office of Dietary Supplements: Vitamin C Fact Sheet for Health Professionals
7. NIH Office of Dietary Supplements: Vitamin E Fact Sheet for Health Professionals
8. NIH Office of Dietary Supplements: Selenium Fact Sheet for Health Professionals
9. NIH Office of Dietary Supplements: Vitamin B12 Fact Sheet for Health Professionals
10. ^ Review of nutritional factors and hair loss
11. ^ Nutritional factors in hair and scalp health
12. ^ Vitamin D deficiency: symptoms, causes, and treatment
13. ^ Micronutrients and hair-loss research
14. ^ Vitamin deficiencies associated with hair loss
15. ^ Iron, vitamins, minerals, and hair-loss evidence
16. ^ Zinc and other micronutrients in hair loss
17. ^ Healthdirect: Zinc deficiency
18. ^ Biotin and hair-loss evidence (2017-06-14)
19. ^ Vitamin deficiencies and hair loss overview
20. ^ NIH Office of Dietary Supplements: Biotin fact sheet
21. ^ Vitamin C, vitamin E, and hair-health evidence
22. ^ Nutritional deficiencies linked to hair loss (2023-09-25)
23. ^ Selenium balance and hair-loss evidence