Urinary excretion of biotin after intake of free and protein-bound biotin in healthy women. - A study on bioavailability of food biotin -

抄録

Biotin functions as an essential cofactor for carboxylases in mammals. Dietary biotin exists in protein-bound and free forms and the ratio of free to total biotin varies among foods. In this study, we measured the urinary excretion of biotin in healthy women after the intake of biotin powder (the ratio of free biotin; 100%), boiled egg (40.3%) or almond (0.5%), each of which contains 50 μg of biotin, and analyzed the effect of chemical forms of biotin on biotin bioavailability. When the biotin powder was ingested, the peak of urinary excretion was shown at the point of 2 hours after intake. Meanwhile, when foods were ingested, the peak was at 4 hours. Biotin excretion after the ingestion of almond tended to be high compared with that of boiled egg, even though the ratio of free biotin in almond was almost zero. These findings indicate that the absorption of food biotin was influenced by chemical forms of biotin and other nutrients.