Hochman LG, et al. Brittle nails: response to daily biotin supplementation. Cutis. 1993;51(4):303-5.

Abstract

A recent study from Switzerland demonstrated a 25 percent increase in nail plate thickness in patients with brittle nails who received biotin supplementation. Analysis of all visits to a nail consultation practice over a six-month period revealed forty-four patients with this condition who had been prescribed the B-complex vitamin biotin. Of these, thirty-five who took daily supplementation were subjectively evaluated. Twenty-two of thirty-five (63 percent) showed clinical improvement and thirteen (37 percent) reported no change in their condition. The results of this small, retrospective study suggest a positive response to biotin in the treatment of brittle nails in some patients. https://www.ncbi.nlm.nih.gov/pubmed/8477615

Shelley WB, et al. Uncombable hair syndrome: observations on response to biotin and occurrence in siblings with ectodermal dysplasia. J Am Acad Dermatol. 1985;13(1):97-102.

Abstract

Three children are reported with uncombable hair syndrome, consisting of slow-growing, straw-colored scalp hair that could not be combed flat. The hairs appeared normal on light microscopy but on scanning electron microscopy were triangular in cross section, with canal-like longitudinal depressions. Oral biotin, 0.3 mg three times a day, produced significant improvement after 4 months in one patient, with increased growth rate and with strength and combability of the hair, although the triangular shape remained. The other two patients were unique in having associated ectodermal dysplasia. Their hair slowly improved in appearance and combability over 5 years without biotin therapy. https://www.ncbi.nlm.nih.gov/pubmed/4031156

Patel DP, et al. A review of the use of biotin for hair loss. Skin Appendage Disord. 2017;3(3):166-169.

ABSTRACT

BACKGROUND: Biotin has gained commercial popularity for its claimed benefits on healthy hair and nail growth. Despite its reputation, there is limited research to support the utility of biotin in healthy individuals.

OBJECTIVE: To systematically review the literature on biotin efficacy in hair and nail growth.

METHODS: We conducted a PubMed search of all case reports and randomized clinical trials (RCTs) using the following terms: (biotin and hair); (biotin and supplementation and hair); (biotin supplementation); (biotin and alopecia); (biotin and nails); (biotin and dermatology), and (biotin recommendations).

RESULTS: We found 18 reported cases of biotin use for hair and nail changes. In all cases, patients receiving biotin supplementation had an underlying pathology for poor hair or nail growth. All cases showed evidence of clinical improvement after receiving biotin.

CONCLUSIONS: Though its use as a hair and nail growth supplement is prevalent, research demonstrating the efficacy of biotin is limited. In cases of acquired and inherited causes of biotin deficiency as well as pathologies, such as brittle nail syndrome or uncombable hair, biotin supplementation may be of benefit. However, we propose these cases are uncommon and that there is lack of sufficient evidence for supplementation in healthy individuals. https://www.ncbi.nlm.nih.gov/pubmed/28879195

Boccaletti V, et al. Familial uncombable hair syndrome: ultrastructural hair study and response to biotin. Pediatric Dermatology. 2007;24(3):E14-E16.

Abstract

We report a family affected to the fourth generation by uncombable hair syndrome. This syndrome is characterized by unruly, dry, blond hair with a tangled appearance. The family pedigree strongly supports the hypothesis of autosomal dominant inheritance; some members of the family had, apart from uncombable hair, minor signs of atopy and ectodermal dysplasia, such as abnormalities of the nails. The diagnosis was confirmed by means of extensive scanning electron microscopy. A trial with oral biotin 5mg/day was started on two young patients with excellent results as regards the hair appearance, although scanning electron microscopy did not show structural changes in the hair. After a 2‐year‐period of follow‐up, hair normality was maintained without biotin, while nail fragility still required biotin supplementation for control. http://onlinelibrary.wiley.com/doi/10.1111/j.1525-1470.2007.00385.x/abstract