Intrinsic factor is the most obscure — yet most important — glycoprotein in the human body. It has only one primary function that is essential for good health. Produced by the parietal cells of the stomach as well as the salivary glands, the intrinsic factor has a brief, but very important life. Intrinsic factor is key for supporting energy, metabolism, and mental health by working with one nutrient — vitamin B12. (more…)