Dietary Supplement Promotes Healthy Hair & Nails Biotin is a member of the B vitamin family that functions in the manufacture and utilization of fats and amino acids. Biotin deficiency is characterized by dry, scaly skin and seborrhea. Biotin supplementation has been shown to increase the strength of nails and promote healthy hair. All Natural Factors products are manufactured according to Canadian Health Protection Branch Good Manufacturing Practices (GMP), among the highest standards in the world.