Biotin is a water-soluble b vitamin (vitamin b7) that human cannot synthesize and depend on dietary and supplements intake.
It was established as a vitamin after 40 years of additional research after its initial discovery in 1927 .
Dietary biotin exists in protein-bound and free forms. However, most of the biotin in foods is bound to protein and very little dietary biotin is in the free form [1,2].
Toxicity is rare due to the limited intestinal absorption of biotin[1,3].