Vegan Hair Loss: Causes, Prevention, and Solutions

Hair loss is one of the most common concerns raised by people transitioning to a vegan diet — and one of the most misunderstood. In most cases, it is not caused by veganism itself but by specific nutritional gaps that are easy to identify and correct. Here is a thorough, evidence-based guide to why it happens and exactly how to fix it.

Is veganism really the cause?

First, some context. Hair loss affects roughly 50% of men and 25% of women by age 50, regardless of diet (American Academy of Dermatology). Androgenetic alopecia (genetic pattern hair loss) is by far the most common cause and has nothing to do with nutrition. Stress-related telogen effluvium — where a shock to the body causes widespread shedding 2–3 months later — is the second most common cause.

That said, any major dietary change can trigger telogen effluvium, particularly if it involves a sudden calorie deficit or the loss of key nutrients. This is not unique to veganism — crash diets, bariatric surgery, and eliminating food groups of any kind can cause the same phenomenon.

The five nutrient deficiencies linked to hair loss

Research in the journal Dermatology Practical and Conceptual(Almohanna et al., 2019) identified the key nutrients whose deficiency is most strongly associated with hair loss. All five are obtainable on a vegan diet with proper planning.

1. Iron

Iron deficiency is the most common nutritional cause of hair loss worldwide. A 2006 study in the Journal of the American Academy of Dermatology (Trost et al.) found that even without anemia, low serum ferritin (stored iron) correlates with diffuse hair loss, particularly in premenopausal women.

The NIH recommends that vegetarians and vegans consume 1.8 times the standard RDA because plant-based (non-heme) iron is less bioavailable than the heme iron found in meat. This means women need approximately 32mg/day and men need approximately 14mg/day.

Best vegan iron sources:

• Pumpkin seeds: 8.1mg per 100g
• Firm tofu: 5.4mg per 100g
• Lentils (cooked): 3.3mg per cup
• Spinach (cooked): 6.4mg per cup
• Quinoa (cooked): 2.8mg per cup
• Dark chocolate (70%+): 11.9mg per 100g
• Fortified cereals: 8–18mg per serving (varies by brand)

2. Zinc

Zinc plays a crucial role in hair follicle growth and repair. A 2013 study in Annals of Dermatology (Park et al.) found that serum zinc levels were significantly lower in people with hair loss compared to controls, and that zinc supplementation improved hair growth in deficient individuals.

Vegans are at higher risk of zinc insufficiency because phytates in whole grains and legumes reduce zinc absorption by up to 50% (Hunt, Journal of Nutrition, 2003). However, soaking, sprouting, and fermenting these foods significantly reduces phytate content.

Best vegan zinc sources:

• Pumpkin seeds: 7.8mg per 100g
• Cashews: 5.6mg per 100g
• Hemp seeds: 10mg per 100g
• Chickpeas (cooked): 2.5mg per cup
• Oats (dry): 3.6mg per 100g
• Fortified cereals: 2–11mg per serving

3. Protein

Hair is made primarily of keratin, a structural protein. Severe protein deficiency causes hair to enter the telogen (resting) phase prematurely, leading to diffuse shedding. A 2017 review in Dermatology Practical and Conceptual confirmed the link between protein malnutrition and hair loss.

For most vegans eating a varied diet, protein deficiency is unlikely. The WHO recommends 0.83g per kg of body weight per day. A 70kg adult needs about 58g — easily achieved with lentils, tofu, tempeh, beans, and whole grains. See our top 25 vegan protein sources for a comprehensive list.

4. Biotin (Vitamin B7)

Biotin deficiency causes brittle hair and hair loss, though true deficiency is rare. The adequate intake (AI) for biotin is 30mcg per day for adults. Biotin is widely available in plant foods:

• Sweet potatoes: 2.4mcg per 100g
• Almonds: 1.5mcg per 28g
• Peanuts: 5mcg per 28g
• Sunflower seeds: 2.6mcg per 28g
• Oats: 7.8mcg per 100g
• Bananas: 0.2mcg per medium banana
• Nutritional yeast: up to 21mcg per tablespoon (varies by brand)

Note: there is no strong evidence that biotin supplementation improves hair growth in people who are not deficient. The "biotin for hair growth" marketing is largely unsupported by clinical evidence. A 2017 review in Skin Appendage Disorders (Patel et al.) concluded that biotin supplementation only benefits those with a documented deficiency.

5. Omega-3 fatty acids

Omega-3 fatty acids (particularly EPA and DHA) support hair follicle health and reduce inflammation that can contribute to hair loss. A 2015 study in the Journal of Cosmetic Dermatology found that omega-3 and omega-6 supplementation significantly reduced hair loss and improved hair density in women after 6 months.

ALA (alpha-linolenic acid) is found abundantly in flaxseeds, chia seeds, and walnuts. However, the conversion of ALA to EPA and DHA in the body is low — only about 5–10% for EPA and less than 1% for DHA (Davis and Kris-Etherton, American Journal of Clinical Nutrition, 2003). For this reason, an algae-based DHA/EPA supplement is recommended for vegans. See our supplements guide.

The role of nutrition and diet in treating hair loss represents a dynamic and growing area of research. Micronutrient deficiency is a well-known, modifiable risk factor for hair loss that should be screened for in clinical practice.

What to do if you are losing hair

1. Get blood work done. Ask your doctor to test serum ferritin (not just hemoglobin), zinc, vitamin D, B12, and thyroid function. These are the most informative tests for nutrition-related hair loss.
2. Track your intake for a week. Use an app like Cronometer to see if you are hitting your targets for iron, zinc, protein, and calories. Many people are surprised by what they find.
3. Correct any deficiencies. Supplement where needed (iron only if blood work confirms low ferritin — excess iron is harmful). Increase dietary intake of the foods listed above.
4. Be patient. Hair has a long growth cycle. Even after correcting deficiencies, it takes 3–6 months for new growth to become visible. The hair you lost during telogen effluvium will typically regrow once the underlying cause is resolved.
5. See a dermatologist if hair loss continues after 6 months of nutritional correction, as the cause may not be dietary.