Created: 13 January 2017
Biotin deficiency is a rare nutritional disorder caused by a deficiency of the water-soluble B vitamin termed biotin. This article discusses biotin deficiency caused by deficiency of the enzyme biotinidase (see also Biotinidase Deficiency). Over 140 different genetic defects have been noted with biotinase. 
At least 25 countries have included biotinidase deficiency in their screening programs for neonatal disease.
Biotin deficiency rarely, if ever, occurs in healthy individuals who consume a regular diet unless they are being treated either with certain anticonvulsants or with broad-spectrum antibiotics. The extremely low prevalence of biotin deficiency is probably the result of a combination of factors. First, the daily requirement for biotin is low (approximately 150-300 µg/d). Second, almost all foods contain significant quantities of biotin, and many widely consumed foods are relatively rich in biotin. Third, the intestinal flora synthesizes significant quantities of biotin, and at least a portion of that biotin is believed to be absorbed into the bloodstream. Fourth, a significant fraction of the body's biotin is recycled; that is, a given molecule of biotin may be repeatedly used before it is eventually lost from the body in the feces or urine.
A new mouse model of this disease has been noted and could help research on this disease.