Biotin is a water-soluble vitamin B which is also known as vitamin B7. It is involved in the synthesis of fatty acids and gluconeogenesis. Biotin is found in plants and animals. Its deficiency causes retardation in growth, alopecia and neurological impairment in humans and animals.Biotin-2′,2′,3′,3′-d4is an isotope of vitamin B7 wherein C-2′, C-2′, C-3′, C-3′ protons are replaced by deuterium.Biotin-2′,2′,3′,3′-d4can be used as a stable isotope internal standard for accurate data interpretation in specific biological samples.