Although estimated average requirements for biotin have been proposed, the human
requirements for biotin in specific populations and at various ages remain uncertain, in part
because indicators of biotin status have not been validated. With the use of improved
methods for measuring biotin and metabolites, a recent study indicated that decreased
urinary excretion of biotin and bisnorbiotin is an early and sensitive indicator of biotin
deficiency, but decreased serum concentration of biotin is not. Increased urinary excretion of …