Translations:Biotin/24/en

Diagnosis

Low serum and urine biotin are not sensitive indicators of inadequate biotin intake. However, serum testing can be useful for confirmation of consumption of biotin-containing dietary supplements, and whether a period of refraining from supplement use is long enough to eliminate the potential for interfering with drug tests. Indirect measures depend on the biotin requirement for carboxylases. 3-Methylcrotonyl-CoA is an intermediate step in the catabolism of the amino acid leucine. In the absence of biotin, the pathway diverts to 3-hydroxyisovaleric acid. Urinary excretion of this compound is an early and sensitive indicator of biotin deficiency.