Characterization of Vitamin B₁₂ Compounds in Commercially Available Livestock Livers Used as Foods

Abstract

Although cow livers are a good source of vitamin B12, it is unclear whether the liver contains inactive corrinoid compounds, such as pseudovitamin B12, most commonly found in foods. Thus, we characterized vitamin B12 compounds in cow, pig, and chicken livers using high-performance liquid chromatography (HPLC) and liquid chromatography–tandem mass spectrometry (LC–MS/MS) after immunoaffinity purification. A primary peak of vitamin B12 (approximately 90%) and several minor peaks were observed during the HPLC of the compounds purified from these livers. Furthermore, LC–MS/MS indicated that these livers contained various corrinoids (approximately 10%), such as factors III, A, S, pseudovitamin B12, and vitamin B12 monocarboxylic acids. This study is the first to report that commercially available livestock liver contains various corrinoid compounds that are inactive in humans.