Nov 11 / Star Khechara

Can Raw Eggs Cause Brittle Nails? The Truth About Avidin and Biotin Deficiency

Understanding Biotin and Its Role in Skin, Hair and Nail Health

Biotin (vitamin B7) is a water-soluble member of the B-complex family essential for fatty acid synthesis, amino acid metabolism and keratin production, all crucial for maintaining the integrity of skin, hair and nails [1].

While overt biotin deficiency is rare in well-nourished populations, suboptimal intake or interference with absorption can lead to brittle nails, hair thinning, dry skin and dermatitis [2]. Because biotin acts as a coenzyme for carboxylase enzymes involved in energy metabolism, its deficiency can also result in fatigue, neurological symptoms and impaired barrier repair [3].

For practitioners working in nutritional skincare and aesthetics, understanding the nutrient’s mechanisms and potential inhibitors is key to addressing underlying causes of skin and hair concerns.

How Raw Egg Whites Can Block Biotin Absorption

Raw egg whites contain a glycoprotein called avidin, which binds extremely tightly to biotin, forming an insoluble complex that prevents intestinal absorption [4].
This binding is among the strongest non-covalent interactions known in nature; one molecule of avidin can bind four molecules of biotin, effectively locking it away from use in the body [5].

Cooking denatures avidin, rendering it inactive and safe. However, raw or lightly cooked eggs (as used in smoothies, homemade mayonnaise, aioli or traditional tonics) can contribute to functional biotin deficiency over time [6].

Symptoms may include:

  • Hair loss or poor hair quality
  • Brittle, splitting nails
  • Dry, scaly or inflamed skin
  • Low mood or fatigue (in chronic cases)

Biotin-Rich Plant and Whole Food Sources

Encouraging clients to eat biotin-rich foods is an effective and sustainable strategy for maintaining healthy skin, hair and nails, particularly if they avoid eggs or dairy.

Top dietary sources include:

  • Almonds and walnuts
  • Sweet potatoes
  • Spinach and kale
  • Avocados
  • Sunflower seeds
  • Legumes (lentils, beans, peas)
  • Mushrooms
  • Oats and whole grains


These foods also provide synergistic nutrients such as vitamin E, zinc and healthy fats, which support collagen synthesis and barrier function [7].

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Why Dietary Analysis Is Essential in Skin, Hair and Nail Consultations

Without a proper dietary review, it’s easy for practitioners to overlook dietary habits that may impair nutrient absorption, like raw egg consumption.

A comprehensive dietary analysis helps the practitioner:

  • Identify biotin inhibitors (such as raw egg whites or alcohol excess)
  • Assess micronutrient sufficiency and dietary variety
  • Recognize restrictive or unbalanced dietary patterns
  • Design evidence-based nutrition protocols tailored to the client’s physiology and goals

Incorporating this step into your client assessments not only improves outcomes but also enhances your professional credibility as a functional skin-health practitioner.

Key Takeaways for Practitioners

  •  Biotin supports keratin structure and the resilience of skin, hair and nails.
  •  Raw egg whites contain avidin, which binds to biotin and prevents absorption.
  •  Cooking eggs neutralises avidin.
  •  Encourage biotin-rich whole foods like almonds, sweet potatoes and spinach.
  •  Always conduct dietary analysis to uncover hidden nutrient-blocking habits.

References

  1. Mock DM. Biotin: From Nutrition to Therapeutics. J Nutr. 2017 Aug; 147(8): 1487-1492. doi: 10.3945/jn.116.238956. Epub 2017 Jul 12. PMID: 28701385; PMCID: PMC5525106.
  2. Patel DP, Swink SM, Castelo-Soccio L. A Review of the Use of Biotin for Hair Loss. Skin Appendage Disord. 2017 Aug;3(3):166-169. doi: 10.1159/000462981. Epub 2017 Apr 27. PMID: 28879195; PMCID: PMC5582478.
  3. Zempleni, J., Hassan, Y. I., & Wijeratne, S. S. (2008). Biotin and biotinidase deficiency. Expert Review of Endocrinology & Metabolism, 3(6), 715–724. https://doi.org/10.1586/17446651.3.6.715
  4. Green, N. M. (1975). Avidin. Advances in Protein Chemistry, 29, 85–133.
  5. Chivers CE, Koner AL, Lowe ED, Howarth M. How the biotin-streptavidin interaction was made even stronger: investigation via crystallography and a chimaeric tetramer. Biochem J. 2011 Apr 1;435(1):55-63. doi: 10.1042/BJ20101593. PMID: 21241253; PMCID: PMC3062853.
  6. Baugh CM, Malone JH, Butterworth CE Jr. Human biotin deficiency. A case history of biotin deficiency induced by raw egg consumption in a cirrhotic patient. Am J Clin Nutr. 1968 Feb; 21(2): 173- doi: 10.1093/ajcn/21.2.173. PMID: 5642891.
  7. Sakurai-Yageta M, Suzuki Y. Molecular Mechanisms of Biotin in Modulating Inflammatory Diseases. Nutrients. 2024 Jul 27;16(15):2444. doi: 10.3390/nu16152444. PMID: 39125325; PMCID: PMC11314543.

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Article by Star Khechara

Professional agehacker, author, speaker, founder of skin nutrition institute
About me
Ex-skincare formulator and beauty author turned skin-nutrition educator: Star distilled her 20+ years of skin-health knowledge into the world’s first international accredited skin-nutrition school to teach skin therapists, facialists, face yoga practitioners and estheticians how to help their clients feed the skin from within for cellular-level rejuvenation and vibrant beauty. 
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