One of the many “beauty vitamins,” biotin, a substance from the B vitamin group, plays a unique role in the care of healthy skin and strong nails, through its participation in the synthesis of key proteins. How does it work and why should you consider supplementing it if you have a problem with tired skin or brittle nails? We will check this in today’s article.
Contents
How does biotin affect skin health?
Biotin (vitamin B7) acts as a cofactor for enzymes involved in key metabolic processes in the body, primarily in fatty acid synthesis, amino acid metabolism, and gluconeogenesis. These processes are directly important for skin function, which – as an organ with a high rate of cell renewal – requires a constant supply of energy and efficiently functioning lipid synthesis mechanisms. Fatty acids are an essential component of the skin’s hydrolipid barrier, responsible for maintaining proper hydration levels and protection against external factors. A proper level of biotin in the body ensures the smooth functioning of these metabolic pathways, which helps maintain the integrity of the skin barrier and the proper condition of epidermal cells.
The importance of biotin for skin health, and for the entire body, is particularly evident in situations of its deficiency, which can lead to symptoms such as:
- dryness,
- flaking skin,
- inflammation,
- increased fragility of hair and nails.
In such cases, increasing biotin intake can support the normalization of metabolic processes occurring in the skin, thereby contributing to a gradual improvement in its appearance and protective functions. In people without deficiencies, the effect of biotin on the skin is usually indirect and subtle, as a healthy body meets its demand for this vitamin from diet and intestinal synthesis. This means that biotin does not act as a “cure for skin problems,” but is one of the essential elements for the proper course of processes that determine good skin condition. Its intake in appropriate amounts is rather a preventive measure, although in certain situations (e.g., dietary changes, digestive system diseases disturbing its absorption and synthesis, etc.) supplementation in doses exceeding the average daily requirement may be indicated as a method of treating symptoms of emerging deficiency.
Biotin in nail regeneration and strengthening
Nails are keratin structures whose proper growth and mechanical resistance depend on intensively occurring metabolic processes in the nail matrix. Biotin indirectly participates in keratin synthesis and in the metabolism of amino acids and lipids, which are necessary for the formation of a compact, well-structured nail plate. In case of biotin deficiency, these processes may be disrupted, resulting in thinner, more brittle nails prone to splitting. The weakened structure of the plate results not so much from the lack of keratin itself, but from improper cell maturation and poorer quality of the bonds building its layers. As a result, tissue is formed in which micro-damage, water, and other unfavorable conditions cause delamination or damage to the plate, which should be resistant to them.
Observational and interventional studies indicate that in people with brittle nails and a confirmed or probable biotin deficiency, an improvement in their hardness and thickness may appear after several weeks of regular supplementation. Due to the slow growth of fingernails (average approx. 2-3 mm per month), the first noticeable effects are usually observed after about 8-12 weeks, and fuller plate regeneration may require several months. As with skin, biotin does not work acutely or cosmetically – its effect on nails consists in gradually restoring proper metabolic conditions that enable their natural growth and strengthening1.
Biotin dosage for skin and nails
The body’s demand for biotin in healthy individuals is relatively small and, according to current nutritional standards, is about 35-45 µg per day (the lower threshold applies to children and adolescents, the higher to breastfeeding women. Current nutritional standards for the Polish population indicate a dose of 40µg as optimal for an adult)2, which can usually be met from a well-balanced diet. However, in the context of supplementation aimed at improving the condition of skin and nails, higher doses are used, most often in the range of 1-5 mg (1000-5000 µg) per day, which were used in studies evaluating the effect of biotin on nail brittleness. These doses (slightly higher than in supplements such as Best B-Complex) are considered safe in adults, although their justification primarily concerns situations of increased demand or suspected deficiency.
It is also worth remembering that biotin is naturally found in many food products, such as:
- eggs (especially yolks),
- nuts,
- seeds,
- whole-grain cereal products,
- legumes,
- organ meats,
These products are worth including in your diet – they can be an additional, physiological source of this vitamin, even after completing deficiency replacement therapy. Their inclusion in the diet can also be a preventive measure, reducing the risk of deficiency or its recurrence.
In beauty industry supplementation, biotin is often combined with other ingredients supporting skin and nails, such as zinc, selenium, silicon, vitamin C, or sulfur amino acids, which together affect the processes of keratin and collagen synthesis. Such combinations do not accelerate the action of biotin, but can help create more complete metabolic conditions for the regeneration and proper growth of nails and maintaining optimal skin hydration and regenerative capabilities.
Sources:
- KG.Thompson, N.Kim, Dietary supplements in dermatology:A review of the evidence for zinc, biotin, vitamin D, nicotinamide, and Polypodium. Journal of American Academy of Dermatology nr. 84/2021, z.4.
- SR. Lipner, Rethinking biotin therapy for hair, nail, and skin disorders, Journal of American Academy of Dermatology nr 78/2018, z. 6.
- Almohanna HM i in., The Role of Vitamins and Minerals in Hair Loss: A Review, 2019
- E. Rychlik, K. Stoś i in., Normy żywienia dla populacji Polski, Narodowe Centrum Edukacji Żywieniowej 2024 r.