Biotin deficiency complicating parenteral alimentation: Diagnosis, metabolic repercussions, and treatment

Biotin deficiency was identified and treated in three patients receiving total parenteral nutrition, all of whom exhibited alopecia totalis, hypotonia, and developmental delay. Two patients had scaly periorificial dermatitis, while one had an intermittent scaly rash. Despite adequate zinc and essential fatty acid levels, all patients showed decreased urinary biotin and increased organic acids, indicating enzyme deficiencies. Biotin therapy (100 μg/day, with one patient receiving higher initial doses) resolved symptoms, though one patient continued to excrete abnormal organic acids. The study suggested that plasma biotin levels might not accurately reflect biotin status and that the recommended pediatric biotin supplement (20 μg/day) might be insufficient during TPN.