Hair Loss

by Jack Norris, RD

Contents

• Summary
• Introduction
• Hair Loss and Nutrition
  • Zinc Deficiency and Hair Loss
  • Iron Deficiency and Hair Loss
  • Iodine Deficiency and Hair Loss
  • B-vitamins and Hair Loss
• Washing Frequency
• Bibliography

Summary

Occasionally, people who become vegetarian or vegan report experiencing hair loss. If there’s a dietary cause, it’s most likely due to low zinc, iron, or iodine status. Vitamin B2, B5, and biotin have also been implicated in hair loss and might be worth supplementation. See Nutrition Tips for Vegans for how vegans can meet iron, zinc, and iodine needs. Expensive supplements are probably unnecessary unless recommended by a dermatologist. Washing hair less to prevent hair loss doesn’t work and can make the loss appear worse than it actually is.

Introduction

Hair loss among women is not an unusual problem. In one survey, 34% of women reported increased hair loss compared to five years earlier (Rushton, 2002).

The reasons for hair loss are complicated and can vary from person to person, so it’s important to see a doctor who can diagnose the specific problem.

There are many types of hair loss, but the two most commonly impacted by nutrition are:

• Telogen effluvium: Normally, 80% of hair follicles are in the anagen (growing) phase. Telogen effluvium is when follicles change to the telogen (pre-shedding) phase earlier than normal (Neve, 1996).
• Female pattern baldness: A reduction in hair density, mainly affecting the crown and frontal scalp (Siavash, 2017). Female pattern baldness usually starts after menopause (Cleveland Clinic, 2024).

Telogen effluvium is probably the most relevant form of hair loss with respect to what some vegans might experience due either to rapid weight-loss or potential, mild nutrient deficiencies. Telogen effluvium can happen after surgery, especially bariatric surgery. Telogen effluvium can be acute onset, occurring within the first 3 to 4 months or chronic onset, occurring 6 to 11 months after surgery. Chronic onset is more likely to be due to specific nutrition deficiencies (Cohen-Kurzrock, 2021; Neve, 1996).

Prolonged and protracted labor and fever can also cause telogen effluvium; the hair almost always grows back spontaneously within 6 months after the cause (Neve, 1996).

Other conditions which can lead to hair loss are hypothyroidism, polycystic ovarian disease, some medications, and physiological and emotional stress (Siavash, 2017).

Hair Loss and Nutrition

There are a number of nutrient deficiencies that might lead to hair loss. There’s no reason to think that doing anything more than correcting the deficiency will benefit hair loss. Be wary of expensive supplements that probably don’t do much more than a typical multivitamin unless prescribed by a dermatologist.

Zinc Deficiency and Hair Loss

Zinc deficiency has been implicated in some cases of hair loss (Neve, 1996; Siavash, 2017). Zinc intake can also be marginal among some vegans. For vegans experiencing mild amounts of hair loss, supplementing with zinc at 5 to 25 mg per day might result in an improvement.

Neve et al. (1996) conducted a study on 47 patients with hair loss due to bariatric surgery. The patients had been taking vitamin and iron supplements with no improvement. They were prescribed 200 mg of zinc sulfate 3 times per day and hair loss reversed within 6 months. However, there was no control group. Five patients experienced the return of hair loss after cessation of zinc supplementation. After restarting zinc, their hair loss reversed again. Despite that lack of a control group, it seems safe to assume that at least five of these patients’ hair loss was due to zinc deficiency.

The tolerable upper intake level for zinc is 40 mg per day; this study used 600 mg of zinc sulfate per day, an amount no one should take without the guidance of a physician.

Siavash et al. (2017) conducted a study on 73 women with hair loss, aged 15 to 45 years. They randomized the participants to four groups for four months:

• Medication: 1 ml of 2% minoxidil solution twice daily on diverse parts of the scalp. Hair density, especially, and thickness improved.
• Zinc: 50 mg per day. Hair density and thickness improved.
• Vitamin B5: 100 mg per day. Hair density and thickness improved.
• Zinc (50 mg) plus vitamin B5 (100 mg) twice per week. Hair density and thickness improved, but not a statistically significant amount. This is likely due to the regimen being taken only twice per week.

There was no control group, so it’s possible the hair loss would have improved without supplementation, but the reduced improvement among the group taking zinc and vitamin B5 only twice per week suggests that daily zinc and vitamin B5 probably helped.

Iron Deficiency and Hair Loss

Although results are mixed (Olsen, 2010), iron deficiency is linked to hair loss among some women. In one study, 72% of women with low iron stores (serum ferritin less than 40 mcg/l) had reduced hair density (Rushton, 2002).

The amino acid lysine plays a part in the absorption of iron and zinc. In some women, iron supplementation alone does not lead to an increase in iron stores. In one study, adding lysine (1.5 to 2 g/day for 6 months) to iron supplementation in such women increased iron stores and decreased hair loss (Rushton, 2002).

Among plant foods, lysine is only found in high amounts in legumes, and a vegan who doesn’t eat many legumes could find themselves falling short on lysine. See our protein recommendations for obtaining enough lysine.

Iodine Deficiency and Hair Loss

As mentioned above, hypothyroidism might result in hair loss. If iodine intakes are too low, it could results in hypothyroidism. Taking 75 to 150 µg per day from a supplement of potassium iodide should prevent any hair loss problems that could be due to iodine deficiency.

B-vitamins and Hair Loss

A number of B-vitamins have been implicated in some cases of hair loss.

Hair loss was found in African children following a vitamin B5 (pantothenic acid) and vitamin B2 (riboflavin) deficiency (Rushton, 2002). Although it’s rare, some vegan diets might be low in B2. Above, we mentioned an improvement among women experiencing hair loss with supplementation of vitamin B5 and zinc.

Biotin deficiency is reported to cause dermatitis and hair loss in experimentally induced states, but establishing the presence of a deficiency in humans with a balanced diet hasn’t been demonstrated. However, 1–2 mg per day for 2 months of biotin has anecdotal clinical support for otherwise unresponsive scaling (loss of the outer layer of skin) and may be worth consideration (Rushton, 2002).

A multivitamin will normally contain all the B2, B5, and biotin that someone on a relatively normal vegan diet could require.

Washing Frequency

Reducing the frequency of hair washing doesn’t help preserve hair and can increase the fear of hair loss because a higher amount of hair will be lost all at once when washed (Rushton, 2002).

Bibliography

Cohen-Kurzrock RA, Cohen PR. Bariatric Surgery-Induced Telogen Effluvium (Bar SITE): Case Report and a Review of Hair Loss Following Weight Loss Surgery. Cureus. 2021 Apr 21;13(4):e14617.

Drake L, Reyes-Hadsall S, Martinez J, Heinrich C, Huang K, Mostaghimi A. Evaluation of the Safety and Effectiveness of Nutritional Supplements for Treating Hair Loss: A Systematic Review. JAMA Dermatol. 2023 Jan 1;159(1):79-86. Not cited.

Karim M, Klein EJ, Widawsky J, Shapiro J, Sicco KL. Veganism in Dermatology: Special Considerations for the Vegan Hair Loss Patient. Skinmed. 2024 Aug 2;22(3):180-186. Lists various supplements used in hair loss and whether they’re vegan. Doesn’t provide evidence for effectiveness.

Neve HJ, Bhatti WA, Soulsby C, Kincey J, Taylor TV. Reversal of Hair Loss following Vertical Gastroplasty when Treated with Zinc Sulphate. Obes Surg. 1996 Feb;6(1):63-65.

Olsen EA, Reed KB, Cacchio PB, Caudill L. Iron deficiency in female pattern hair loss, chronic telogen effluvium, and control groups. J Am Acad Dermatol. 2010 Dec;63(6):991-9. Epub 2010 Oct 13.

Rushton DH. Nutritional factors and hair loss. Clin Exp Dermatol. 2002 Jul;27(5):396-404.

Siavash M, Tavakoli F, Mokhtari F. Comparing the Effects of Zinc Sulfate, Calcium Pantothenate, Their Combination and Minoxidil Solution Regimens on Controlling Hair Loss in Women: A Randomized Controlled Trial. J Res Pharm Pract. 2017 Apr-Jun;6(2):89-93.

Sivamani RK, Ablon G, Nong Y, Maloh J, Hazan A, Raymond I. A Prospective, Multi-Center Study to Evaluate the Safety and Efficacy of a Vegan Nutraceutical to Improve Hair Growth and Quality in Females Following a Plant-Based Diet. J Drugs Dermatol. 2024 Aug 1;23(8):661-668. Not cited. No control group. Supplement was Nutrafol Women’s Vegan Capsules. Ingredients weren’t listed in the paper but the label suggests a multivitamin might have been as effective. Participants could eat red meat up to three times per week but detailed participant data wasn’t provided.